A 1

A 1 A 1 ([=a] w[u^]n). A registry mark given by underwriters (as at Lloyd's) to ships in first-class condition. Inferior grades are indicated by A 2 and A 3. [1913 Webster]

Note: A 1 is also applied colloquially to other things to imply superiority; prime; first-class; first-rate. [1913 Webster]