Main Entry: ¹del·ta

Pronunciation: \ˈdel-tə\

Function: noun

Etymology: Middle English deltha, from Greek delta, of Semitic origin; akin to Hebrew dāleth daleth

Date: 13th century

1 : the 4th letter of the Greek alphabet — see alphabet table
2 : something shaped like a capital Greek delta; especially : the alluvial deposit at the mouth of a river
3 : an increment of a variable —symbol Δ
4 : delta wave

— del·ta·ic \del-ˈtā-ik\ adjective