We found 9 dictionaries that define the word number 1:

General (7 matching dictionaries)

1. number 1: Vocabulary.com
2. number 1: Dictionary.com
3. Number 1 (Big Bang album), Number 1 (Goldfrapp song), Number 1 (Nelly song), Number 1 (O-Zone album), Number 1 (Tinchy Stryder song): Wikipedia, the Free Encyclopedia
4. number 1: Rhymezone
5. number 1: FreeDictionary.org
6. number 1: Mnemonic Dictionary
7. number 1: TheFreeDictionary.com

Computing (1 matching dictionary)

8. number 1: Encyclopedia

Slang (1 matching dictionary)

9. number 1: Urban Dictionary

(Note: See number_1s as well.)

Definitions from WordNet (number 1) ▸ noun:  the first element in a countable series Opposite: last, final, bottom, end, tail Phrases: atomic number 1, a number 1, Number 1 Record, Number 1 Angel, Look Out for Number 1, more... ▸ Words similar to number 1 ▸ Usage examples for number 1 ▸ Idioms related to number 1 ▸ Wikipedia articles (New!) ▸ Words that often appear near number 1 ▸ Rhymes of number 1 ▸ Invented words related to number 1