negligible (adj.)

"heedless disregard of duty, inactivity, indifference, habit of omitting to do things which ought to be done," mid-14c., necligence, from Old French negligence "negligence, sloth; injury, injustice" (12c.), and directly from Latin neclegentia, neglegentia "carelessness, heedlessness, neglect," from neglegentem (nominative neglegens) "heedless, careless, unconcerned," present participle of neglegere "to neglect" (see neglect (v.)).

word-forming element making adjectives from verbs, borrowed in Middle English from Old French -ible and directly from Latin adjective suffix -ibilis (properly -bilis); see -able.