Tuna Walls is the name for a woman with a smelly vagina and when you pull out it smells like tuna

The term usually encompasses the entire vagina however has often been noted to just mean the interior of the female genitalia

A man who is definitely not a virgin, is 'getting some' or likes to sleep women...lots of them

A pushy that smells like tuna

A large man that would need to be weighed like a large wild fish off the fishing boat.

Sweat tuna can be used to replace such phrases like

No worries
No problem
Yea for sure