We found 8 dictionaries that define the word day in and day out:

General (7 matching dictionaries)

1. day in and day out: Vocabulary.com
2. day in and day out: Dictionary.com
3. day in and day out: Rhymezone
4. day in and day out: FreeDictionary.org
5. day in and day out: Mnemonic Dictionary
6. day in and day out: TheFreeDictionary.com
7. day in and day out: Merriam-Webster

Miscellaneous (1 matching dictionary)

8. day in and day out: Idioms

Definitions from WordNet (day in and day out) ▸ adverb:  without respite ("He plays chess day in and day out") Opposite: sporadically, intermittently, irregularly ▸ Words similar to day in and day out ▸ Usage examples for day in and day out ▸ Idioms related to day in and day out ▸ Wikipedia articles (New!) ▸ Words that often appear near day in and day out ▸ Rhymes of day in and day out ▸ Invented words related to day in and day out