(third-person singular simple present opens up, present participle opening up, simple past and past participle opened up)
- (intransitive) To open.
- Some vacancies have opened up due to retirements.
- Open up the door!
- (intransitive) To reveal oneself; to become communicative.
- After three hours of questioning, he finally opened up.
- (intransitive) To commence firing weapons.
- As the convoy entered the pass, we opened up on them with everything we had.