DictionaryAI

known

SayNOHN/noʊn/UK/nəʊn/

Adjectivebetter known, best known

Noun pluralknowns

4 meanings of known

Practice

  1. 1
    after haveverb
    Past participle of know. Use this form after 'have' (has known) or 'be' (is known).

    I have known her since we were little kids.

    They had known about the plan for weeks.

    UsageUse after have, has, had or be: has known (not incorrect: has knew).

    Note
  2. 2
    adjective
    That people already know about or have found out.

    The known causes of the illness are listed in the booklet.

    We followed the known steps to fix the problem.

    UsageSay known to for the people who know: known to few people. Also well known, widely known.

    Oppositeunknown

    Note
  3. 3
    nouncountable
    A fact or thing that people already understand.

    The doctors explained the knowns and unknowns about her illness.

    Our only known is that the door was locked; the rest is a guess.

    UsageOften plural, next to its opposite: knowns and unknowns.

    Similargiven, certainty, fact

    Oppositeuncertainty

    Note

Less common meaning

  1. 4
    given (math)nouncountable
    A number in a math problem whose value you already have.

    Like a puzzle piece you already have that helps you find the missing ones.

    Put the known on one side and the missing number on the other.

    Once you have one known, the rest becomes easier to solve.

    Oppositeunknown

    Note

known is a form of know

know, verb: To have facts or information in your mind and be sure they are true. Full entry

Forms
knowknows he/she/itknowing -ing formknew past tenseknown past participle
Spelling
know → known: irregular (no -ed)

Practice

Can you tell the meanings of known apart? Answer 4 quick questions from this page, or write your own sentence and AI will check it.

Origin

This is the past participle of "know." It comes from Old English cnāwen.

Checked 5 Nov 2026 · 2 facts