Antithetical

прилагательное 1) [философия] антитетический 2) прямо противоположный

Большой англо-русский словарь

Antithetical

also antithetic adjective 1. constituting or marked by antithesis 2. being in direct and unequivocal opposition Synonyms: see oppositeantithetically adverb

Merriam-Webster's Collegiate Dictionary