A one

[ey wuhn] /ˈeɪ ˈwʌn/
adjective
1.
noting a vessel regarded by a shipping-classification society as being equipped to the highest standard and with equipment maintained in first-class condition.
2.
Also, A number one. Informal. first-class; excellent; superior:
The meals there are A one.
Also, A-one, A 1, A-1.
Origin
1830-40
British Dictionary definitions for a-one

A1

/ˈeɪˈwʌn/
adjective
1.
in good health; physically fit
2.
(informal) first class; excellent
3.
(of a vessel) with hull and equipment in first-class condition
Slang definitions & phrases for a-one

A-1

adjective

a-number-1


Related Abbreviations for a-one

A-one

first class (excellent)
Idioms and Phrases with a-one

A-one

Also, A-1; A-number-one. First-class, of the best quality, as in This is an A-one steak. The term comes from Lloyd's, the British insurance company, which in its 1775 shipping register designated the condition of a ship's hull by a letter grade (A, B, etc.) and of its cables, anchor, and other equipment by a number grade (1, 2, etc.). By the early 1800s A-1, the best possible grade, was being transferred to anything of superior quality.