We found 12 dictionaries that define the word a-one:

General (10 matching dictionaries)

1. A-one: American Heritage Dictionary of the English Language
2. A-one, A-one: Collins English Dictionary
3. A-one: Vocabulary.com
4. A-One, A-one, a-one: Wordnik
5. A-one: Dictionary.com
6. A-ONE: Wikipedia, the Free Encyclopedia
7. A-one: Rhymezone
8. a-one: FreeDictionary.org
9. a-one: Mnemonic Dictionary
10. A-one: TheFreeDictionary.com

Art (1 matching dictionary)

11. A-one: Artist Search

Computing (1 matching dictionary)

12. A-one: Encyclopedia

Definitions from WordNet (A-one) ▸ adjective:  of the highest quality Opposite: lowest, worst, bottom-tier, inferior ▸ Words similar to a-one ▸ Usage examples for a-one ▸ Idioms related to a-one ▸ Wikipedia articles (New!) ▸ Popular nouns described by a-one ▸ Words that often appear near a-one ▸ Rhymes of a-one ▸ Invented words related to a-one