Typically a girl before she become slut. This is usually the middle ground before becoming a slut. for example, in high school when a girl doesn't want to have sex but still crushes on multiple boys even though she has one or two other boyfriends. She promptly leaves any of them when she gets bored. They crave attention and usually restrain from sex to save their reputation.
Guy 1: So how is it with you and Lily?
Guy 2: Oh yeah, I can't believe I ever fell for her because she was just another Manhopper
Guy 1: Yeah, that sucks...
Can refer to any large caliber gun or bullet that will immediately "stop" a person with one hit. You might live from receiving a limb shot. But there is little to no chance of surviving a hit to the head or body. .50 AE, .45 ACP and .357 Magnum are popular calibers know as manstoppers. The larger the better.
1.A term referring to people of mixed italian and irish descent such as good ol' Robert DeNiro.
2. New hamburger when McDonald's and Burger King merge.