forceful

authoritative, definitive

sound, valid, well-founded

important, significant, weighty

material, pertinent, relevant

decided, insistent, marked, pointed

absolute, categorical (also categoric), clear, plain, unambiguous, unequivocal

arresting, compelling, conspicuous, impelling, noticeable, striking

hard, ironclad, mighty, powerful, tough, unyielding

animated, brisk, energetic, frisky, jaunty, jazzy, lively, peppy, perky, spirited, sprightful, sprightly, springy, vital, vivacious, zippy

assured, certain, confident, sanguine, secure, sure

cogent, controlling, dominating, masterful

dominant, predominant, regnant, sovereign (also sovran), supreme

eminent, important, momentous