It has more than one meaning.
Meaning one -
A type of food that some people can't have due to religion. Meat comes from animals. People can sometimes be allergic to meat.
Meaning two -
Another name for a penis. This is how it is used in a sentence:
"Hey bro, I whipped out my meat so fast, my girl got all wet! I shoved my meat in her vagina (pussy or fanny is another name for vagina) and she cummed. I also let her gulp my meat!"
Basically beef but raw, so instead saying everthing thats happened u just sum it up say it all in a few words.
ALICIA: what's the meat?
Me: Bea's a nonce
A greeting used by the greatest of men
“Hi how are you”
“Meat”