Meaning

noun a military operation (often involving new supplies of men and materiel) to strengthen a military force or aid in the performance of its mission

noun information that makes more forcible or convincing

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 *-mn̥ Proto-Indo-European *-mn̥tom Proto-Italic *-mentom Latin -mentum Old French -mentbor. Middle English -ment English -ment English reinforcement From reinforce + -ment.

Etymology from Wiktionary, CC BY-SA 3.0