backstop (n.)youdaoicibaDictYouDict[backstop 词源字典]
1819, in cricket, from back (adj.) + stop (n.). In U.S. baseball, from 1889, "fence behind the catcher;" figurative extension to "catcher on a baseball team" is from 1890. The verb is attested from 1956 in the sense of "support." Related: Backstopped; backstopping.[backstop etymology, backstop origin, 英语词源]