(a.) Incapable of being described or explained\.

exceptional extraordinary fabulous incommunicable indefinable ineffable inenarrable inexpressible innominable legendary marvelous mythical noncommunicable noteworthy phenomenal portentous prodigious remarkable stupefying stupendous undefinable unexampled unmentionable unnameable unparalleled unprecedented unspeakable untellable unutterable unwhisperable wonderful