Definition of "tilde"

The grapheme of character ~.

1. A diacritical mark (˜) placed above a letter to modify its pronunciation, such as by palatalization in Spanish words or nasalization in Portuguese words.  quotations  examples

   Quotations

   • The tilde was used similarly in Portuguese on vowels to show that the letter bearing the tilde should be pronounced nasally.

     2021, Claire Cock-Starkey, Hyphens & Hashtags, Bodleian Library, page 162

2. A punctuation mark that indicates range (from a number to another number).  examples

3. May be used to represent approximation (mathematics).  examples

(logic) The character used to represent negation, usually ~ or ¬.  examples