trietericEtymologyFrom Ancient Greek τριετηρικός (trietērikós) from τρι- (tri-, “tri-”) + ἔτος (étos, “year”) + -ικός (-ikós).trieteric means Synonym of triennal (“related to or characterized by an three-year period”) Lexicurio rates it Sui generis — a strength score of 87 out of 100.adjSynonym of triennal (“related to or characterized by an three-year period”)nounSynonym of triennial (“third anniversary”).