n.
Pronunciation: m ə - ' th ī - ə - ˌ n ē n
Function: noun
Etymology: International Scientific Vocabulary, from me thyl + thion- + 2 -ine
Date: 1928
: a crystalline sulfur-containing essential amino acid C 5 H 11 NO 2 S that occurs in the levorotatory form as a constituent of many proteins