Webster’s Revised Unabridged Dictionary · 1913
Rounder
Round′er (·ẽr), 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.