I. yes ‧ ter ‧ day 1 S1 W1 /ˈjestədi, -deɪ $ -ər-/ BrE AmE adverb
[ Language: Old English ; Origin: giestran dæg , from giestran 'yesterday' + dæg 'day' ]
on or during the day before today ⇨ tomorrow :
What did you do yesterday?
yesterday morning/afternoon/evening
Anna left yesterday afternoon.
⇨ I wasn’t born yesterday at ↑ born 2 (5)
II. yesterday 2 BrE AmE noun [uncountable]
1 . the day before today ⇨ tomorrow :
yesterday’s meeting
They arrived the day before yesterday.
2 . the recent past:
the great champions of yesterday
3 . yesterday’s news information that is old and no longer interesting