abrupt (adj.)youdaoicibaDictYouDict[abrupt 词源字典]
1580s, from Latin abruptus "broken off, precipitous, disconnected," past participle of abrumpere "break off," from ab- "off" (see ab-) + rumpere "break" (see rupture (n.)). Related: Abruptly; abruptness.[abrupt etymology, abrupt origin, 英语词源]
bangs (n.)youdaoicibaDictYouDict
"hair cut straight across the forehead," 1878 (singular), American English, attested from 1870 of horses (bang-tail), perhaps from notion of abruptness (as in bang off "immediately, without delay," though this expression is attested only from 1886). See bang.