1. To stand up quickly. I hopped up to answer the door.

2. To reach someone or something by hopping. I was just sitting here when, all of a sudden, a bunny hopped up!

3. slang To modify something in order to increase its power or performance. A noun or pronoun can be used between "hop" and "up." He's spent a fortune hopping up his car for drag racing. We've hopped our computers up to run incredibly complex programs at lightning speeds.

4. slang To be high on some substance, often a drug. I've never seen her so energized before—I hope she's not hopped up on something. Kevin is all hopped up on coffee—how many cups do you think he had?