2b Definition

abbreviation
Second base.
Webster's New World
Second baseman.
Webster's New World
(baseball) Second base, second baseman.
Wiktionary

(baseball) Double, a baseball statistic indicating a runner has safely advanced to second base.

Wiktionary

(UK) A grade of pencil with lead that makes darker marks than a pencil grade B but lighter marks than a pencil of grade 3B.

Wiktionary