Rounder \Round"er\, n.

1. One who rounds; one who comes about frequently or regularly.

2. A tool for making an edge or surface round.

3. pl. An English game somewhat resembling baseball; also, another English game resembling the game of fives, but played with a football.

Now we play rounders, and then we played prisoner's base. --Bagehot.

Source: Webster's Revised Unabridged Dictionary (1913)