difficult

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Hard to do or accomplish; demanding considerable effort or skill; arduous: "To entertain is far more difficult than to enlighten” ( Anthony Burgess). See Synonyms at hard.
2. adj. Hard to endure; trying: fell upon difficult times.
3. adj. Hard to comprehend or solve: a difficult puzzle.
4. adj. Hard to please, satisfy, or manage: a difficult child.
5. adj. Hard to persuade or convince; stubborn.

Century Dictionary and Cyclopedia

1. Not easy; requiring or dependent on effort; hard; troublesome; arduous. Specifically— Hard as to doing or effecting; wanting facility of accomplishment: with an infinitive: as, it is difficult to convince him; a thing that is difficult to do or to find.
2. Hard to do, perform, or overcome; attended with labor, pains, or opposition; laborious: as, a difficult undertaking.
3. Hard to please or satisfy; not compliant; unaccommodating; rigid; austere: as, a person of difficult temper.
4. Hard to persuade or induce; stubborn in yielding; obstinate as to opinion: as, he was difficult to convince.
5. Hard to understand or solve; perplexing; puzzling: as, a difficult passage in an author; a difficult question or problem.
6. Synonyms Difficult, Hard, Arduous (see arduous), laborious, toilsome; obscure, knotty.
7. To make difficult; impede.
8. To perplex; embarrass.

Wiktionary

1. adj. hard, not easy, requiring much effort
2. adj. hard to manage, uncooperative, troublesome; eg. said of a person, a horse, etc.
3. v. obsolete, transitive To make difficult; to impede; to perplex.

GNU Webster's 1913

1. adj. Hard to do or to make; beset with difficulty; attended with labor, trouble, or pains; not easy; arduous.
2. adj. Hard to manage or to please; not easily wrought upon; austere; stubborn.
3. v. rare To render difficult; to impede; to perplex.

WordNet 3.0

1. adj. hard to control
2. adj. not easy; requiring great physical or mental effort to accomplish or comprehend or endure