A hopper is someone who dates boys/girls incredibly fast. A hopper hops from different boys/girls. You are a hopper if you date like 2 people in the span of like 4 days.
Did you know Sarah dated Henry then broke upwith him? Less than a day later she was dating Krish. She is such a hopper.
In an elevator of a high-rise building, a random person come in, in the middle of your elevator ride just to go a few floors up or down costing you valuable time.