Meaning

noun any result that follows its cause after an interval

noun a delayed effect of a drug or therapy

originEtymology tree Proto-Indo-European *h₂ep Proto-Indo-European *-o Proto-Indo-European *h₂epó Proto-Indo-European *-teros Proto-Indo-European *h₂ep(o)teros Proto-Germanic *after Old English æfter Middle English after English after ▲ Old English æfter Old English æfter- Middle English after- English after- English effect English aftereffect From after- + effect.

Etymology from Wiktionary, CC BY-SA 3.0