"difficulty"; consider this list:--

"Nouns. Difficulty, hardness (and nouns formed from similar adjectives);
impracticability, &c. (see _impossibility_); tough-, hard-, uphill-
work; hard-, herculean-, Augean-task; task of Sisyphus, Sisyphean labour,
tough job, teaser, rasper, dead lift.

"Dilemma, embarrassment; perplexity, &c. (see _uncertainty_);
intricacy; entanglement; cross fire; awkwardness, delicacy, ticklish card
to play, knot, Gordian knot, _dignus vindice nodus_, net, meshes,
maze; coil, &c. (see _convolution_); crooked path.

"Nice-, delicate-, subtle-, knotty point; vexed question, _vexata
quaestio_, poser, puzzle, &c. (see riddle); paradox; hard-, nut to
crack; bone to pick, crux, _pons asinorum_, where the shoe pinches.

"Nonplus, quandary, strait, pass, pinch, pretty pass, stress, brunt;
critical situation, crisis; trial, rub, emergency, exigency, scramble.

"Scrape, hobble, slough, quagmire, hot water, hornet's nest; sea-, peck of
troubles: pretty kettle of fish; pickle, stew, _imbroglio_ mess, ado;
false position; set fast, stand; dead,-lock,-set; fix, horns of a dilemma,
_cul de sac_; hitch; stumbling block, &c. (see _hindrance_)."

The catalogues of allied adjectives and of allied verbs are even longer
than the foregoing.

The Introduction to the _Thesaurus_, by the way, though deserving of
study, is a dull and cumbrous piece of work and not necessary to the
usefulness of the book.