i

Less common meanings

5. 5
   instead of mepronoun · Inonstandardsubjective

   Used by the speaker or writer to refer to themselves as the grammatical object, after a verb or a preposition.

   Thanks for coming out with Dana and I last night!

   She invited both Marcus and I to the wedding, which surprised everyone.

   UsageCommon in pairs after a verb or preposition (Dana and I), but careful speech and writing use me: Dana and me.

   Note

   The pairing is old: Shakespeare writes "between you and I" in The Merchant of Venice. A lone object I turns up in song lyrics, from Bob Marley, who puts it after a verb of stealing, to Slipknot's "The Devil in I."

6. 6
   alphabet letternouncountable

   The name of the letter I/i of the Latin script.

   In English, i rhymes with 'my' and 'why,' which surprises many Spanish speakers.

   Reciting the alphabet, the children giggled when they reached i, because it sounded like 'eye.'

   Note

   The letter's name joins other words with a hyphen: an i-dot is the dot of an i, and i-mutation and i-umlaut are named after it. Written out as a word, the name even has a plural of its own, ies. Source

   Checked 30 Oct 2026 · 3 facts

   • An i-dot is the dot of an i. en.wiktionary.org
   • The letter name occurs in the hyphenated terms i-mutation and i-umlaut. en.wiktionary.org
   • The written letter name has the plural ies. en.wiktionary.org
7. 7
   independentnoun · IUScountable or uncountableabbreviation

   Short for independent, a politician or voter who belongs to no political party, as in I-Maine.

   Rep. Tom Harlan (I-Colo.) announced Tuesday that he would seek a second term.

   On the seating chart, each senator is marked D, R, or I.

   UsageIn news copy it sits in parentheses with the state (I-Colo.), beside D and R.

   Note

   The independent it stands for is a politician tied to no party. Source

   Checked 2 Nov 2026 · 1 fact

   • An independent politician has no formal political party affiliation. en.wikipedia.org
8. 8
   imaginary numbersymbol

   In mathematics, the imaginary unit: a fixed square root of -1, plotted on the vertical axis of a graph.

   Every complex number can be written as a real number plus a real multiple of i.

   Multiplying by i turns a point on the complex plane a quarter turn counterclockwise around zero.

   Note

   Which square root of -1 gets the name is a choice: i and -i behave identically in algebra, so one is fixed as i and kept. Complex numbers are then written a + bi, with i often in italics or bold, while electrical engineers write j instead, because i already means electric current. Source

   Checked 30 Oct 2026 · 3 facts

   • The two square roots of −1 are algebraically interchangeable, so either can be chosen as i; this follows from complex conjugation being an automorphism. www-personal.umd.umich.edu
   • Every complex number can be written a + bi, with real a and b. openlab.citytech.cuny.edu
   • Engineers use j for the imaginary unit to avoid confusion with i for electric current. kth.se
9. 9
   iodinesymbol · I

   In chemistry, the symbol for the element iodine.

   Among the halogens, I sits below Br and above At.

   In the formula for potassium iodide, K and I appear in a one-to-one ratio.

   Note

   In formulas it takes the usual subscripts and charges: I₂ is the two-atom molecule that pure iodine is made of, and I⁻ is the iodide ion found in salts such as potassium iodide. A Roman I in parentheses after an element's name is something else entirely, an oxidation state. Source

   Checked 30 Oct 2026 · 3 facts

   • Elemental iodine consists of diatomic molecules with formula I₂. en.wikipedia.org
   • I⁻ is the iodide ion and is present in potassium iodide. en.wikipedia.org
   • A parenthesized Roman numeral after an element's name indicates its oxidation state. iupac.org
10. 10
    noun · Icountable or uncountable

    In metaphysics, the ego: a person's conscious self, the one who thinks and experiences.

    The poem gives voice to a divided I, torn between duty and desire.

    For the philosopher, the I that doubts is the one thing that cannot be doubted.

    Similarme

    Note

    Here the pronoun has become a noun for the self that says I. It takes an article and a plural like any noun, often inside quotation marks, and suits writing about a divided self: Thomas Boston found "two I's in every believer," and S. A. Steel asked in 1916 whether he had a conscious "I" and an unconscious one. Source

    Checked 30 Oct 2026 · 3 facts

    • Thomas Boston wrote that there are "two I's in every believer." en.wiktionary.org
    • Steel's passage was published in 1916. en.wiktionary.org
    • S. A. Steel asked whether he had both a conscious and an unconscious "I." en.wiktionary.org
11. 11
    oxidation statesymbol · I

    In inorganic chemistry, the Roman numeral that specifies an oxidation state of +1.

    The chemist reduced the copper(II) solution until only copper(I) ions remained.

    Mercury(I) compounds contain pairs of mercury atoms bonded to each other.

    UsageIn parentheses right after the name, with no space: copper(I), said copper one.

    Note

    It is needed only for elements with more than one common oxidation state, which is why copper and mercury carry it while sodium normally does not. Source

    Checked 2 Nov 2026 · 3 facts

    • An oxidation-state numeral is needed to distinguish elements' common positive oxidation states. open.maricopa.edu
    • Copper has more than one common oxidation state. en.wikipedia.org
    • Mercury has more than one common oxidation state. en.wikipedia.org
12. 12
    list markernumerallowercaseordinal

    Letter form of the ordinal ninth.

    Paragraph 4(i) comes right after 4(h) and sets out the late fee.

    On the answer sheet, she circled (i), the last of the nine choices.

    Note

    It means ninth only inside a lettered run, where (i) follows (h). In a list counted i, ii, iii, the same letter is the Roman numeral one, so only its neighbors show which reading is meant. Source

    Checked 30 Oct 2026 · 3 facts

    • In alphabetical enumeration, i occupies the ninth position, following h. en.wiktionary.org
    • Lowercase i, ii, iii can form a Roman-numeral sequence. en.wikipedia.org
    • The Roman numeral I represents one. en.wikipedia.org
13. 13
    loop countersymbol

    A common variable name for a generic index, especially the counter in a loop.

    The loop keeps running while i is less than the length of the list.

    In the formula, i runs from 1 to n, picking out each measurement in turn.

    Note

    Programmers and mathematicians reach for it first and then move along the alphabet: when one loop sits inside another, the inner loop counts with j, and a third level counts with k.

14. 14
    electric currentsymbol · I

    In physics and electronics, the symbol for electric current, usually measured in amperes.

    Divide the voltage by the resistance to find I.

    The datasheet lists the maximum I the part can carry without overheating.

15. 15
    identity matrixsymbol · I

    In linear algebra, the symbol for the identity matrix.

    Eigenvalues are found by setting the determinant of A minus λ times I equal to zero.

    The program checks its work by confirming that the matrix times its inverse gives I.

    Note

    The identity matrix is the square matrix with ones down the main diagonal and zeros everywhere else, sometimes with a subscript for its size, as in I₃. It does for matrices what 1 does for numbers: multiplying by it changes nothing. Source

    Checked 30 Oct 2026 · 2 facts

    • The identity matrix is square, has ones on the main diagonal and zeros elsewhere, and may carry a size subscript, such as I₃. math.libretexts.org
    • Multiplying a matrix by an identity matrix of the appropriate size leaves it unchanged. lancaster.ac.uk
16. 16
    moment of inertiasymbol · I

    In physics, the symbol for moment of inertia.

    Torque equals I times angular acceleration, just as force equals mass times acceleration.

    The engineers lowered I by moving the flywheel's mass closer to its axle.

    Note

    Mass belongs to an object, but this quantity also depends on the axis of turning, because what counts is how far the mass sits from that axis. A rod is harder to swing about one end than about its middle, and its I about the end is larger to match. Source

    Checked 30 Oct 2026 · 2 facts

    • Moment of inertia depends on the chosen axis and the distribution of mass around it. en.wikipedia.org
    • A uniform rod has greater moment of inertia about an end than about its middle, making it harder to accelerate rotationally. openstax.org
17. 17
    interjection · Iobsolete

    Obsolete spelling of aye: yes, used to agree or to vote in favor of something.

    Note

    Old texts can trip a modern reader here: a capital I standing alone may be the answer yes rather than the speaker, so "I, sir" can mean "Yes, sir." The word is now spelled aye, as in the "aye aye" that answers an order. Source

    Checked 30 Oct 2026 · 3 facts

    • Capital I was formerly a spelling of aye, meaning yes. en.wiktionary.org
    • “I, sir” can mean “Yes, sir” in an old text. en.wikisource.org
    • “Aye aye” acknowledges an order. en.wiktionary.org
18. 18
    noun

    Short for instruction, in computing, a single basic operation that a processor carries out, as in I-cache.
19. 19
    noun

    Short for instrumental case: the grammatical case that marks the means or tool by which an action is done, used as a label in grammar tables.
20. 20
    symbol

    In physics, the symbol for isotopic spin.