adj. difficult to deal with; "a troublesome infection"; "a troublesome situation"

adj. causing irritation or annoyance; "tapping an annoying rhythm on his glass with his fork"; "aircraft noise is particularly bothersome near the airport"; "found it galling to have to ask permission"; "an irritating delay"; "nettlesome paperwork"; "a pesky mosquito"; "swarms of pestering gnats"; "a plaguey newfangled safety catch"; "a teasing and persistent thought annoyed him"; "a vexatious child"; "it is vexing to have to admit you are wrong"

adj. resulting in punishment; "the king imposed a punishing tax"

adj. requiring full use of your abilities or resources; "ambitious schedule"; "performed the most challenging task without a mistake"

adj. hard to deal with; especially causing pain or embarrassment; "awkward (or embarrassing or difficult) moments in the discussion"; "an awkward pause followed his remark"; "a sticky question"; "in the unenviable position of resorting to an act he had planned to save for the climax of the campaign"

adj. making great mental demands; hard to comprehend or solve or believe; "a baffling problem"; "I faced the knotty problem of what to have for breakfast"; "a problematic situation at home"

adj. having concealed difficulty; "a catchy question"; "a tricky recipe to follow"

adj. bristling with perplexities; "the thorny question of states' rights"

adj. hard to endure; "fell upon trying times"

adj. impressively difficult; "a tall order"

adj. extremely difficult; requiring the strength of a Hercules; "a herculean task"

adj. requiring great effort; "a hard-fought primary"

adj. very unpleasant; "hellish weather"; "stop that god-awful racket"

adj. very difficult; severely testing stamina or resolution; "a rugged competitive examination"; "the rugged conditions of frontier life"; "the competition was tough"; "it's a tough life"; "it was a tough job"

adj. causing difficulty in finding an answer or solution; much disputed; "the vexed issue of priorities"; "we live in vexed and troubled times"

adj. having few parts; not complex or complicated or involved; "a simple problem"; "simple mechanisms"; "a simple design"; "a simple substance"

adj. easy and not involved or complicated; "an elementary problem in statistics"; "elementary, my dear Watson"; "a simple game"; "found an uncomplicated solution to the problem"