IPA: /ˈɛf.ər.tləs/
KK: /ˈɛfərtləs/
Describing something that can be done easily and without much work or struggle.
She made an effortless jump over the hurdle during the race.
Comparative: more effortless
Superlative: most effortless
Effortless → It is formed from "effort" (from Old French *esforcier*, meaning to exert oneself) and "-less" (meaning without). The word "effortless" means without effort or requiring no exertion.
Think of someone who does something 'without' ('-less') 'exerting themselves' ('effort') — that's why effortless means something is done easily.