flagellum (n.)youdaoicibaDictYouDict
"long, lash-like appendage," 1837, from Latin flagellum "whip, scourge," also figurative, diminutive of flagrum "a whip," from PIE root *bhlag- "to strike" (cognates: Latin flagitium "shameful act, passionate deed, disgraceful thing," flagitare "to demand importunately;" Old Norse blakra "to flutter with the wings," blekkja "to impose upon;" Lithuanian blaškau "to and fro").
flagitious (adj.)youdaoicibaDictYouDict
"shamefully wicked, criminal," late 14c., from Old French flagicieus or directly from Latin flagitiosus "shameful, disgraceful, infamous," from flagitium "shameful act, passionate deed, disgraceful thing," related to flagrum "a whip, scourge, lash," and flagitare "to demand importunately," all from PIE root *bhlag- "to strike" (see flagellum). Related: Flagitiously; flagitiousness.
importunate (adj.)youdaoicibaDictYouDict
1520s, from importune + -ate, or else from Medieval Latin importunatus, past participle of importunari. Related: Importunately (mid-15c.).