- unfathomable
- adj1. impenetrable, incomprehensible, past or beyond comprehension, unknowable, inscrutable, incognizable, indecipherable, undecipherable, beyond understanding; profound, deep, esoteric, recondite, abstruse, abstract, heavy, Sl. heavy-duty; mystic, mystical, cabalistic, supernatural; occult, cryptic, perdu, secret, hidden, concealed, shrouded; obscure, vague, dim, dark, nebulous, Rare. imperspicu-ous; mysterious, arcane, inexplicable, unexplainable, insolvable, insoluble, unaccountable, inextricable; puzzling, enigmatic, enigmatical.2. bottomless, soundless, unsounded, fathomless, unfathomed, plumbless, unplumbed, measureless, unmeasured; abysmal, cavernous, plunging; deepsea, deep as the sea or ocean, deep as a well.
A Note on the Style of the synonym finder. 2014.