Weigh in Definition 1 of 3Pro Tip 1/3Expressing Opinion Used when someone offers a judgement in an ongoing conversation. At the team meeting, even the intern got to weigh in with his fresh perspective. Pro Tip 2/3Assertive Participation Implies actively contributing, not just agreeing with others. Karen likes to weigh in with her unique ideas during brainstorms. Pro Tip 3/3Conversation Momentum Often signals a new or significant contribution to the discussion. When they started talking about climate change, I had to weigh in.