tilde
Pluraltildes
- 1A written symbol ⟨~⟩, also called a swung dash or wave dash, and known to computer users as a squiggle or twiddle.
Designers sometimes use a tilde as a decorative flourish between section titles.
In the shell, a tilde stands in for your home directory.
Note
The name is the tricky part here. Typographers say swung dash, and Robert Bringhurst's The Elements of Typographic Style (1992) files the character under that name as a stock keyboard character. In mathematics it is the sign of similarity (a ~ b). Strictly, tilde is the accent that rides above a letter. For the free-standing character on the line, it is the everyday name rather than the typographer's.
- 2A wavy diacritical mark ⟨˜⟩ placed over a letter to change the way the letter is pronounced.
In phonetic transcription, a tilde above a vowel marks it as nasal.
The typesetter's font had no tildes, so readers of the atlas mispronounced several place names.
Note
Position is written into this mark's name. English took tilde from Spanish, and behind it stands Latin titulus, "superscript": a mark written above, exactly where the tilde sits on its letter. Title and tittle descend from the same Latin word by other routes, and Portuguese has the cognate til. Riding on a letter, as in Spanish ñ, it is a diacritic; the same name also covers the free-standing ~ symbol.
- 3A symbol placed before a quantity to indicate approximation, in both English prose and mathematics, as in '~30 pounds'.
The report prefixed each figure with a tilde to flag rough estimates.
In his notes he scribbled a tilde before the population count he wasn't sure of.
Note
Placed before a number, it reads 'about' or 'roughly', as in ~30 pounds, and it belongs to informal prose. Formal mathematics more often writes approximate equality as ≈. There, ~ between two terms usually means something stricter: similarity, asymptotic equivalence, or in statistics 'is distributed as'. In technical writing, spelling out 'about' avoids the misreading.
- 4The character encoded as decimal 126 in the 1967 ASCII set and later carried into the Unicode standard.
In ASCII, the tilde sits at decimal 126, near the end of the printable characters.
Unicode kept the tilde at the same code point it held in ASCII.
Note
Programmers usually meet this number in hexadecimal. Decimal 126 is 7E, so Unicode writes the character as U+007E and keeps it in the Basic Latin block it inherited from ASCII. That continuity is why a tilde typed in an old plain-text file still reads correctly today. The code point names the free-standing symbol, not the accent written over a letter.
- 5A punctuation mark indicating a range from one number to another, a use common in Asia where the symbol is also called a wave dash.
Japanese price tags use a tilde to show a range, as in '1000~2000 yen'.
The schedule listed the festival dates with a tilde between the start and end.
Note
Where English writes an en dash for a range (pages 10–20), much of Asia writes this wavy line, as in 1000~2000 yen. In that use it goes by the name wave dash. The distinction matters in software, because Japanese character sets encode the wave dash separately from the plain ASCII tilde. Two marks that look alike on the page may therefore be different characters underneath.
- 6In lexicography, the ⟨~⟩ symbol used to stand for a repetition of the entry word or item, in which use it is also called a swung dash.
Under “break,” the entry lists “~ even” and “~ the ice,” each tilde standing for the headword itself.
The style sheet for the new glossary tells editors to use a tilde, not a hyphen, for every repeated term.
- 7An alternate form of the logical negation operator, usually written ¬, placed before a proposition to negate it.
In propositional logic, a tilde before P denotes the negation of P.
Some textbooks prefer a tilde to the ¬ symbol when writing negations.
Note
Logicians read ~P as 'not P', and it is true exactly when P is false. The choice between ~ and ¬ is notational and varies with the textbook, not with the meaning. Robert Bringhurst notes that the angled ¬ is preferred to avoid confusion, since ~ already does other work in mathematics, where it can mean similarity or approximation.
Less common meanings
Practice
Can you tell the meanings of tilde apart? Answer 4 quick questions from this page, or write your own sentence and AI will check it.
Origin
Borrowed from Spanish tilde, from Latin titulus ("superscript") or from tildar. It is a doublet of titer/titre, title, titlo, tittle, and titulus.