in·appreciable \|in+\adjective Etymology: probably from French inappréciable, from Middle French inappreciable, from in- in- (I) + appreciable — more at appreciable 1.archaic: invaluable 2.: not appreciable : too small to be perceived < became inappreciable at 615° C. — E.B.Shaud > • in·appreciably\“+\adverb