10 letters · 15 points in Scrabble
noun (psychology) a stimulus that strengthens or weakens the behavior that produced it
originEtymology tree Proto-Italic *wre- Latin re-der. Old French re-bor. Middle English re- English re- English inforce English reinforce Proto-Indo-European *-yósder. Proto-Italic *-āzijos Latin -āriusnom. Latin -āriusbor. Proto-Germanic *-ārijaz Proto-West Germanic *-ārī Old English -ere Middle English -ere English -er English reinforcer From reinforce + -er.
Etymology from Wiktionary, CC BY-SA 3.0