What is "tilde"

Tilde \Til"de\, n. [Sp., fr. L. titulus a superscription, title, token, sign. See Title, n.] The accentual mark placed over n, and sometimes over l, in Spanish words [thus, [~n], [~l]], indicating that, in pronunciation, the sound of the following vowel is to be preceded by that of the initial, or consonantal, y.

1864, from Spanish, metathesis of Catalan title, from vernacular form of Medieval Latin titulus "stroke over an abridged word to indicate missing letters," a specialized sense of Latin titulus, literally "inscription, heading" (see title (n.)). The mark itself represents an -n- and was used in Medieval Latin manuscripts in an abridged word over a preceding letter to indicate a missing -n- and save space.

n. 1 The grapheme of character ~. 2 # A diacritical mark ((l mul ˜)) placed above a letter to modify its pronunciation, such as by palatalization in Spanish words or nasalization in Portuguese words. 3 # A punctuation mark that indicates range (from a number to another number). 4 # May be used to represent approximation (mathematics). 5 A key found on some types of keyboards. 6 (context logic English) The character used to represent negation, usually ~ or ¬.

n. a diacritical mark (~) placed over the letter n in Spanish to indicate a palatal nasal sound or over a vowel in Portuguese to indicate nasalization

The tilde (; ˜ or ~) is a grapheme with several uses. The name of the character came into English from Spanish, which in turn came from the Latin titulus, meaning "title" or "superscription".

The reason for the name was that it was originally written over a letter as a scribal abbreviation, as a "mark of suspension", shown as a straight line when used with capitals. Thus the commonly used words Anno Domini were frequently abbreviated to A Dñi, an elevated terminal with a suspension mark placed over the "n". Such a mark could denote the omission of one letter or several letters. This saved on the expense of the scribe's labour and the cost of vellum and ink. Medieval European charters written in Latin are largely made up of such abbreviated words with suspension marks and other abbreviations; only uncommon words were given in full. The tilde has since been applied to a number of other uses as a diacritic mark or a character in its own right. These are encoded in Unicode at and , and there are additional similar characters for different roles. In lexicography, the latter kind of tilde and the swung dash (⁓) are used in dictionaries to indicate the omission of the entry word.