The tilde (, also ) is a grapheme ⟨˜⟩ or ⟨~⟩ with a number of uses. The name of the character came into English from Spanish tilde, which in turn came from the Latin titulus, meaning 'title' or 'superscription'. Its primary use is as a diacritic (accent) in combination with a base letter. Its freestanding form is used in modern texts mainly to indicate approximation. History. Use by medieval scribes. The tilde was originally one of a variety of marks written over an omitted letter or several letters as a scribal abbreviation (a "mark of contraction").
https://en.wikipedia.org/wiki/Tilde