1. To spill or slosh onto someone or something as a result of being moved around jerkily. Hot soup slopped onto the bride after the waiter slipped on an ice cube that had fallen onto the ground. Be careful carrying that bucket of varnish—we don't want any to slop onto the brand-new decking!

2. To cause something to spill or slosh onto someone or something as a result of being moved around jerkily. In this usage, a noun or pronoun is used between "slop" and "onto." You need to be more careful while you're serving, or you're going to slop those drinks onto our guests! I can't believe he slopped paint onto my nice clothes!

3. To serve something messy or sloppy onto something else. In this usage, a noun or pronoun is used between "slop" and "onto." I just need to slop these cheeseburgers onto the buns, and then we'll be ready to eat! The lunch lady slopped some nasty-looking casserole onto my plate and told me to keep moving.