muscular and heavily built; "a beefy wrestler"; "had a tall burly frame"; "clothing sizes for husky boys"; "a strapping boy of eighteen"; "`buirdly' is a Scottish term"
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"
existing for a long time; "hopes for a durable peace"; "a long-lasting friendship"
very long lasting; "less durable rocks were gradually worn away to form valleys"; "the perdurable granite of the ancient Appalachian spine of the continent"
serviceable for a long time; "durable denim jeans"
ill-mannered and coarse and contemptible in behavior or appearance; "was boorish and insensitive"; "the loutish manners of a bully"; "her stupid oafish husband"; "aristocratic contempt for the swinish multitude"
harshly uninviting or formidable in manner or appearance; "a dour, self-sacrificing life"; "a forbidding scowl"; "a grim man loving duty more than humanity"; "undoubtedly the grimmest part of him was his iron claw"- J.M.Barrie
inspiring fear; "the formidable prospect of major surgery"; "a tougher and more redoubtable adversary than the heel-clicking, jackbooted fanatic"- G.H.Johnston; "something unnerving and prisonlike about high grey wall"
extremely impressive in strength or excellence; "a formidable opponent"; "the challenge was formidable"; "had a formidable array of compositions to his credit"; "the formidable army of brains at the Prime Minister's disposal"