1.When you sneak up on a girl in the middle of the night and stab her in the back with a sausage. Repeatedly.
2. A dick or penis.
3. Also can be made into a drink by placing a slim jim into a bloody mary. Generally, it's garnished with cheese on a plastic sword.
Last night I meat stabbed this girl. She got so turned on, she gave me a rusty trombone.
Excuse me, bartender, can I have a meatstabber, extra slim.