Main Entry: the·ta

Pronunciation: \ˈthā-tə, chiefly British ˈthē-tə\

Function: noun

Etymology: Middle English, from Latin, from Greek thēta, of Semitic origin; akin to Hebrew ṭēth teth

Date: 15th century

1 : the 8th letter of the Greek alphabet — see alphabet table
2 : theta rhythm