v.1. To stumble or fall: I tripped up walking upstairs and hurt my ankle.
2. To cause someone to stumble or fall: The soccer player tripped up her opponent with a slide tackle. The broken stair tripped him up.
3. To make a mistake: I would have done better on the test if I hadn't tripped up on the last section.
4. To cause someone to make a mistake: His inability to focus on his work trips him up every time. The unclear phrasing of the question tripped her up.