abstruse deep recondite
abstruse%5:00:00:esoteric:00 deep%5:00:00:esoteric:00 recondite%5:00:00:esoteric:00
abstruzen globok nejasen nerazumljiv skrit temen
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