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