Difficult to do, understand or answer (adj).

 A fact that everyone knows.

To fail to take advantage of a chance or favourable situation.

With a great deal of effort (adv).

To continue to be in a particular place for a period of time without moving away.

To remove something, especially clothes.

To cover part of the body with clothes, shoes, make-up, or something similar.

To not tell anyone information that is meant to be hidden.

To make (someone) known by name to another in person, especially formally.

To go to a meeting or event that has been arranged.