Word.ws English Dictionary

a1

a1 is the alternative letter-case form of A1.

Adjective capitalized: A1

A1 (not comparable)

  1. (informal) In good health.
  2. (informal) In excellent or top condition.
  3. First-class. (Compare A 2 and A 3, which are inferior grades.)

Noun capitalized: A1

A1 (plural A1s)

  1. Under the International Union of Railways (French: Union internationale des chemins de fer, UIC) classification system, a steam locomotive that has two coupled driving wheels followed by two trailing wheels, with no leading wheels; also called an 0-2-2.

Forms of a1

Adjective
alternative formA-1
alternative formA 1
Noun
pluralA1s

Origin of a1

From various rating systems, as that of Lloyd's of London or the condition of insured ships. First attested in 1837.

Questions about a1

What does a1 mean?
A1 means in good health.
What is a1 the alternative letter-case form of?
A1 is the alternative letter-case form of A1.
What part of speech is a1?
A1 can be an adjective or a noun.

Words near a1 in the dictionary

  1. A/S
  2. a/s/l
  3. A/T
  4. A/UX
  5. A/V
  6. a1
  7. A1/C
  8. A1/Cs
  9. a11y
  10. A1A-A1A
  11. A1A-A1As

Source and license

Adapted from Wiktionary: a1 (page history and authors); A1 (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

Last updated:

Cite this entry: “a1.” Word.ws, https://word.ws/a1. Based on Wiktionary, CC BY-SA 4.0.