Definitions

1. noun

the day preceding today, past day, or previous day

“I didn’t do my homework yesterday, so I need to do it tonight.”

2. adverb

on the day before today, in the past day, or previously

“I was sick yesterday and couldn’t attend the party.”

3. adverb

in the past; previously

“She was a famous actress yesterday, but now she’s retired.”

4. adverb

in the recent past, especially in the previous day or night

“I couldn’t find my keys yesterday, so I looked for them everywhere today.”