To get involved with a person or group of people 1. (showing disapproval) "I'm a bit worried about Jeff. He's got in with a really strange group of people" - he's hanging around with a strange group of people, and it not good for him 2. (Making friends with people in order to persuade and influence them, because it's good for your career) If you want to get the best contracts you should get in with those guys. They know all the right people."