n.
Pronunciation: ' yes-t ə r-( ˌ )d ā , -d ē
Function: adverb
Etymology: Middle English yisterday, from Old English giestran dæg, from giestran yesterday + dæg day; akin to Old High German gestaron yesterday, Latin heri, Greek chthes
Date: before 12th century
1 : on the day last past : on the day preceding today
2 : at a time not long past : only a short time ago <I wasn't born yesterday >
– yesterday adjective