1. A diacritical mark (ñ) placed over the letter n in Spanish to indicate the palatal nasal sound (ny), as in cañon, or over a vowel in Portuguese to indicate nasalization, as in lã, pão.
2. A symbol (~) similar to a tilde used in mathematics and logic to indicate negation, inversion or indicating equivalency or similarity between two values.
3. Etymology: from the mid 19th century; from Spanish, an alteration of obsolete Catalan title, which came from Latin titulus, "title, superscription".