The day preceding today.
From middle english yisterday, yesterdei, from old english ġeostran dæġ ("yesterday"), equivalent to yest- + day.
- Yesterday was a beautiful day, with clear blue skies and warm sunshine.
- I can't believe it's already been a year since yesterday.
- Yesterday's news reported a major breakthrough in the medical field.
- She always feels nostalgic when she thinks about yesterday.
- Yesterday, I ran into an old friend at the grocery store.