We found 18 dictionaries that define the word a1:

General (10 matching dictionaries)

1. A1: Merriam-Webster
2. A1: Oxford Learner's Dictionaries
3. A1: Collins English Dictionary
4. A.1, A1(M), A1 (Albania), A1 (Austria), A1 (Bosnia and Herzegovina), A1 (Bulgaria), A1 (Croatia), A1 (Italy), A1 (Newcastle upon Tyne), A1 (Serbia), A1 (Switzerland), A1 (TV channel), A1 (album), A1 (band), A1 (comic), A1 (comics), A1 (disambiguation), A1 (group), A1 (wrestler), A1: Wikipedia, the Free Encyclopedia
5. A1: Stammtisch Beau Fleuve Acronyms
6. A1: TheFreeDictionary.com
7. A1, a1: Wiktionary
8. a1: Dictionary.com
9. a1: Longman Dictionary of Contemporary English
10. A1: Merriam-Webster

Art (1 matching dictionary)

11. Technical Glossary of Theatre Terms (No longer online)

Business (1 matching dictionary)

12. BusinessDictionary.com (No longer online)

Computing (3 matching dictionaries)

13. a1: Free On-line Dictionary of Computing
14. A1 (disambiguation), A1: Encyclopedia
15. Windows API Guide (No longer online)

Miscellaneous (1 matching dictionary)

16. A1-, A1: Acronym Finder

Science (1 matching dictionary)

17. A1: Cytokines & Cells Online Pathfinder Encyclopaedia

Slang (1 matching dictionary)

18. A1: Urban Dictionary

Similar: drawer, Fourier series, retinol, 1A, 0, 1B, 2A, 2B, 3a, 3d, more... Opposite: a2, negative of a1, inverse of a1, antithesis of a1, contradictory to a1 Types: a2, a3, a4, a5, a6, a7, a8, a9, more... Phrases: vitamin a1, Annexin A1, phospholipase a1, a1 security, Adenosine A1 receptor, more... ▸ Words similar to a1 ▸ Usage examples for a1 ▸ Idioms related to a1 ▸ Wikipedia articles (New!) ▸ Words that often appear near a1 ▸ Rhymes of a1 ▸ Invented words related to a1