We found 4 dictionaries that define the word by day:

General (3 matching dictionaries)

1. by day: Merriam-Webster
2. by-day: Wordnik
3. by day: Cambridge Advanced Learner's Dictionary

Miscellaneous (1 matching dictionary)

4. by day: Idioms

Phrases: day by day, by the day, by the end of the day, word sung twice by doris day, to live day by day, more... ▸ Words similar to by day ▸ Usage examples for by day ▸ Idioms related to by day ▸ Wikipedia articles (New!) ▸ Words that often appear near by day ▸ Rhymes of by day ▸ Invented words related to by day