To agree to something, say "okay," or allow something to happen is to accept it. These sentences show how you can use "accept" as a verb:
I accept your offer.
Your application for a credit card was accepted. (Here the verb "accept" is in the passive voice.)
Allen was accepted at Harvard.
Christine accepted John’s offer of marriage.
We can’t accept anymore new students in this class. It’s too full.
Don refuses to accept the fact that his son is gay.
My offer wasn’t accepted. It was rejected.
There are three possibilities for the adjective form of this word: accepted, acceptable, and acceptance.
His behavior was not acceptable, so the school expelled him. (You can also use the word "unacceptable.")
Accepted applications go into this filing cabinet. Unaccepted applications are kept for one year before they are destroyed.
The terms of the agreement are acceptable to all parties involved.
The nominee for the position made a great acceptance speech. He told everyone he would be honored to accept the position.
Note: The pronunciation of "accept" is the same as the word "except." To except something is to exclude it or remove it from a group. Many Americans confuse the spelling of these two words; the meanings, however, are clearly different.