unfathomable

adjectives

of depth; not capable of being sounded or measured
unfathomable
antonym
fathomable
is similar to
too deep to determine the depth of
unsoundable
see also
having great spatial extension or penetration downward or inward from an outer surface or backward or laterally or outward from a center; sometimes used in combination
"a deep well"; "a deep dive"; "deep water"; "a deep casserole"; "a deep gash"; "deep massage"; "deep pressure receptors in muscles"; "deep shelves"; "a deep closet"; "surrounded by a deep yard"; "hit the ball to deep center field"; "in deep space"; "waist-deep"
deep
resembling an abyss in depth; so deep as to be unmeasurable
"the abyssal depths of the ocean"
abysmal, abyssal, unfathomable
impossible to come to understand
unfathomable
is similar to
difficult to understand
"the most incomprehensible thing about the universe is that it is comprehensible"- A. Einstein
incomprehensible, uncomprehensible