We found 11 dictionaries that define the word twenty-four hours:

General (9 matching dictionaries)

1. twenty-four hours: Oxford Learner's Dictionaries
2. twenty-four hours, twenty-four hours: Collins English Dictionary
3. twenty-four hours: Vocabulary.com
4. twenty-four hours: Dictionary.com
5. Twenty-four Hours: Wikipedia, the Free Encyclopedia
6. twenty-four hours: Rhymezone
7. twenty-four hours: FreeDictionary.org
8. twenty-four hours: Mnemonic Dictionary
9. twenty-four hours: TheFreeDictionary.com

Computing (1 matching dictionary)

10. twenty-four hours: Encyclopedia

Miscellaneous (1 matching dictionary)

11. Encyclopedia of Graphic Symbols (No longer online)

Definitions from WordNet (twenty-four hours) ▸ noun:  time for Earth to make a complete rotation on its axis Opposite: 12 hours, half day, day and night ▸ Words similar to twenty-four hours ▸ Usage examples for twenty-four hours ▸ Idioms related to twenty-four hours ▸ Wikipedia articles (New!) ▸ Words that often appear near twenty-four hours ▸ Rhymes of twenty-four hours ▸ Invented words related to twenty-four hours