shopping at a market; "does the weekly marketing at the supermarket"
the commercial processes involved in promoting and selling and distributing a product or service; "most companies have a manager in charge of marketing"
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"
requiring more than usually expected or thought due; especially great patience and effort and skill; "found the job very demanding"; "a baby can be so demanding"