Synonyms of the word

problematical

• adj. doubtful or disputed.
• adj. dubious or ambiguous.

baffling

• v. present participle of baffle.
• adj. puzzling and frustrating.
• n. An act of foiling or thwarting.

debatable

• adj. Controversial. Not fully proved, open to debate, sometimes used humorously.
• adj. Of a person, argumentative.
• adj. A fitting subject for debate.

difficult

• adj. Hard, not easy, requiring much effort.
• adj. (often of a person, or a horse, etc) Hard to manage, uncooperative, troublesome.
• adj. (obsolete) Unable or unwilling.
• v. (obsolete, transitive) To make difficult; to impede; to perplex.

hard

• adj. (of material or fluid) Having a severe property; presenting difficulty.
• adj. (personal or social) Having a severe property; presenting difficulty.
• adj. Unquestionable.
• adj. (of a road intersection) Having a comparatively larger or a ninety-degree angle.
• adj. (slang, vulgar, of a male) Sexually aroused.
• adj. (bodybuilding) Having muscles that are tightened as a result of intense, regular exercise.
• adj. (phonetics, not comparable).
• adj. (art) Having a severe property; presenting a barrier to enjoyment.
• adj. (not comparable) In the form of a hard copy.
• adv. (manner) With much force or effort.
• adv. (manner) With difficulty.
• adv. (obsolete) So as to raise difficulties.
• adv. (manner) Compactly.
• adv. (now archaic) Near, close.
• n. (countable, nautical) A firm or paved beach or slope convenient for hauling vessels out of the water.
• n. (uncountable, drugs, colloquial, slang) crack cocaine.

knotty

• adj. Full of knots.
• adj. Complicated or tricky; complex; difficult.

problematic

• adj. Posing a problem; having or suffering from problem(s).
• n. (chiefly in the plural) A problem or difficulty in a particular field of study.

questionable

• adj. (obsolete) Inviting questions; inviting inquiry.
• adj. Problematic; open to doubt or challenge.
• adj. Of dubious respectability or morality.

tough

• adj. Strong and resilient; sturdy.
• adj. (of food) Difficult to cut or chew.
• adj. Rugged or physically hardy.
• adj. Stubborn.
• adj. (of weather etc) Harsh or severe.
• adj. Rowdy or rough.
• adj. (of questions, etc.) Difficult or demanding.
• adj. (material science) Undergoing plastic deformation before breaking.
• interj. (slang) Used to indicate lack of sympathy.
• n. A person who obtains things by force; a thug or bully.
• v. To endure.
• v. To toughen.