Inapprehensible is a word that denotes something that is difficult or impossible to understand or perceive. Synonyms for this word include incomprehensible, inscrutable, unfathomable, enigmatic, cryptic, opaque, mystifying, baffling, and impenetrable. These words convey a sense of mystery and confusion, highlighting the fact that the thing in question is beyond the realm of understanding. Other synonyms may include unintelligible, incomprehensible, abstruse, mysterious, bewildering, perplexing, inexplicable, and elusive. No matter which synonym is used, the sense of difficulty in understanding remains, emphasizing the complexity and obscurity of the subject at hand.