Definition
Ineffectual, pointless.
How People Actually Use It
Southern slang to describe a person, place, event or item in which there is little or no value; in the same way that tits are of no use on a male hog.
"Gosh I don't know why the boss hired that lazy assed guy to work here, he is as "useless as tits on a boar hog"!"
Source: Urban Dictionary