Causing a problem; problematic; troublesome.
Difficult to train or guide; unruly.
A difficulty that has to be resolved or dealt with.
A puzzling circumstance.
A set of moves required to complete a climb.
A question to be answered, schoolwork exercise.
Objection.
Difficulty in accepting or understanding or refusal to accept or understand.
Lack of subtlety or abstruseness; clarity
Lack of artificial ornament, pretentious style, or luxury; plainness
Lack of complication; efficiency.
The quality or state of being not complex, or of consisting of few parts
The quality or state of being unmixed or uncompounded
Lack of sharpness of mind; lack of ability to think using complex ideas; stupidity