Fallback
来自Big Physics
Safin（讨论 | 贡献）2022年4月29日 (五) 02:46的版本 （建立内容为“Category:etymology == wiktionary == [https://en.wiktionary.org/wiki/fallback ref] From the verb fall back. == etymonline == [https://www.etymonline.com/w…”的新页面）
wiktionary
From the verb fall back.
etymonline
fallback
also fall-back, as a noun, "a reserve," 1851, from verbal phrase, from fall (v.) + back (adv.), which is attested in the sense of "retreat" from c. 1600. As an adjective, from 1767 as a type of chair; 1930 as "that may be used in an emergency."
