baseball (n.)youdaoicibaDictYouDict[baseball 词源字典]
in the modern sense, 1845, American English, from base (n.) + ball (n.1). Earlier references, such as in Jane Austen's "Northanger Abbey," refer to the game of "rounders," of which baseball is a more elaborate variety. Legendarily invented 1839 by Abner Doubleday in Cooperstown, N.Y. Base was used for "start or finish line of a race" from 1690s; and the sense of "safe spot" found in modern children's game of tag can be traced to 14c. (the sense in baseball is from 1868).[baseball etymology, baseball origin, 英语词源]
rounder (n.)youdaoicibaDictYouDict
1620s, "a sentinel," agent noun from round (n.) on notion of "one who makes the rounds." Sense of "chronic drunkard or criminal" is from 1854, on notion of one who is habitually in and out of jails or bars. Rounders, a baseball-like game, attested from 1828.