Meanings
a11
adjectivea1 (not comparable)
- not comparableAlternative letter-case form of A1.
A12
adjectiveA1 (not comparable)
alternative A-1 · alternative A 1
- informalnot comparableIn good health.
- informalnot comparableIn excellent or top condition.
- not comparableFirst-class. (Compare A 2 and A 3, which are inferior grades.)
A13
nounA1 (plural A1s)
plural A1s
- 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.
Synonyms & antonyms
Origin
From various rating systems, as that of Lloyd's of London or the condition of insured ships. First attested in 1837.
Full word history & related roots →Cite this entry
APA
a1. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/a1
MLA
“a1.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/a1. Accessed November 3, 2026.
Chicago
WatkinsX Dictionary, s.v. “a1,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/a1.
Source: a1 on Wiktionary, CC BY-SA 4.0.