jump at someone—
1. attack a person from a distance:
- The animal jumped at him, he squatted down and the cougar went over him, not making contact.
2. criticize a person severely:
- That same author did try to improve things by incorporating changes and everyone jumped at him.
3. (also: jump out at someone) said of smth. very obvious or easy to notice:
- Only the precious few had the special kind of talent that just jumps at you.
jump on someone—
1. pounce on a person (landing on top of the person attacked):
- The Lion jumped up and jumped on him with all four feet.
2. = jump at someone 2:
- I’m sorry, Eddy, I didn’t mean to jump on you that way.
Note: Neither expression is equivalent in meaning to the phrase jump someone—(sl.)
1. attack smb. suddenly in a sneaky fashion (with the intention to rob, etc.):
- When I “jumped” him we didn’t mean to kill or hurt him.
2. cheat or swindle a person:
- The old proprietor … was green, and let the boys about here jump him.