We found 9 dictionaries that define the word all day long:

General (7 matching dictionaries)

1. all day long: Vocabulary.com
2. all day long: Dictionary.com
3. All Day Long (Garth Brooks song), All Day Long (Kenny Burrell album), All Day Long (album), All Day Long: Wikipedia, the Free Encyclopedia
4. all day long: Rhymezone
5. all day long: FreeDictionary.org
6. all day long: Mnemonic Dictionary
7. all day long: TheFreeDictionary.com

Miscellaneous (1 matching dictionary)

8. all day long: Idioms

Slang (1 matching dictionary)

9. all day long: Urban Dictionary

Definitions from WordNet (all day long) ▸ adverb:  during the entire day ▸ Words similar to all day long ▸ Usage examples for all day long ▸ Idioms related to all day long ▸ Wikipedia articles (New!) ▸ Words that often appear near all day long ▸ Rhymes of all day long ▸ Invented words related to all day long