1
- on the day before today在昨天, 在昨日：
he returned to a hero's welcome yesterday.
昨天他回来时人们像英雄般地欢迎他。
1.1
- in the recent past日前, 不久前：
everything seems to have been built yesterday.
一切都好像是昨天才建成的。
1
- the day before today昨天, 昨日：
yesterday was Tuesday.
昨天是星期二。
1.1
- the recent past近日, 日前, 前不久：
yesterday's best-sellers.
前一阵的畅销书。
短语
yesterday morning （或afternoon等）
- in the morning (or afternoon etc.) of yesterday昨天早上（或下午）。
yesterday's man
- a man, especially a politician, whose career is finished or past its peak昨日之星（尤指政治生涯已结束或已过巅峰期的政治家）。
yesterday's news
- a person or thing that is no longer of interest昨日新闻, 过时的人（或事）。
词源
Old English giestran dæg （see YESTER-， DAY）.