Difficult (adjective)

1. Requiring much effort, skill, or determination.
2. Hard to do, understand, or deal with.
3. Hard to bear or endure.
4. Not easy to please.
5. Not easily managed or controlled.

Origin:

Middle english, from latin difficilis, from difficilis (from difficile, it is difficult).

Examples:

1. The math problem was very difficult.
2. The journey was difficult because of the harsh conditions.
3. The task was difficult for her to complete.
4. He has a difficult personality.
5. The horse was difficult to control.