Pronunciation: (til'du),[key] —n. 1. a diacritic (~) placed over an n, as in Spanish mañana, to indicate a palatal nasal sound or over a vowel, as in Portuquese são, to indicate nasalization.
2. See swung dash. 3. Math.a symbol (~) indicating equivalency or similarity between two values.
4. Logic.a similar symbol indicating negation.