1. Get up on the back of, especially a horse
   "hop on a horse";
   - mount, mount up, get on, jump on
    
2. Get on board of (trains, buses, ships, aircraft, etc.)
   "We hopped on the bus just before it left";
   - board, get on

Derived forms: hopped on, hopping on, hops on

Type of: come in, enter, get in, get into, go in, go into, move, move into