figurative. Something intricate, involved, or difficult to trace out or explain; a tangle or difficulty; a knotty point or problem. Gordian knot: see…

a bone to pick (also †gnaw) and variants: (originally) a matter or undertaking requiring close attention or concentration; a problem to be…

An authoritative decision; a judgement pronounced by a tribunal. dark, hard sentence: a difficult problem. (In Bible translations used to render…

With allusion to the difficulty of cracking hard-shelled nuts: a difficult question or problem; a matter or undertaking difficult to accomplish…

Gordian knot n. figurative or allusively: (a) A matter of extreme difficulty. to cut a Gordian knot: to get rid of a difficulty by force or by…

A knotty point, a difficulty, a complication. Cf. node, n. 3. Now rare.

Something that teases, or causes annoyance; something difficult to deal with, a ‘poser’. colloquial. In Pugilistic slang, an opponent difficult…

Something (e.g. a question, a task imposed, a reply) that ‘stumps’ one; a poser.

one of the ingenious puzzles made by the Chinese, in which the problem is to fit together the dissected pieces of a geometrical or other figure, to…

figurative. A setback; a sudden difficulty or obstacle.

colloquial. Something which perplexes or impedes a person; a difficult problem, question, or issue.

colloquial. A poser, settler, floorer. Cf. gruel, v. 1.

A cause of stumbling; a ‘poser’.

That which (or one who) wrings or causes contortion; esp. figurative something that confounds, non-plusses, or ‘doubles up’, a ‘staggerer’ (slang)…