2 : of an obscure nature; "the new insurance policy is written without cryptic or mysterious terms"; "a deep dark secret"; "the inscrutable workings of Providence"; "in its mysterious past it encompasses all the dim origins of life"- Rachel Carson; "rituals totally mystifying to visitors from other lands"
3 : (of darkness) densely dark; "thick night"; "thick darkness"; "a face in deep shadow"; "deep night"
4 : difficult to penetrate; incomprehensible to one of ordinary understanding or knowledge; "the professor's lectures were so abstruse that students tended to avoid them"; "a deep metaphysical theory"; "some recondite problem in historiography"
adjectif
1 : 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
