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"
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"
difficult to penetrate; incomprehensible to one of ordinary understanding or knowledge
