Best definition
Working Stiff
A person who works for a living. A wage earner of some sort.

Fred: I heard they’re handing out $50k to people with bad mortgages. Do you think the average working stiff will see ever a dime??

Steve: No chance in hell.

Working Stiff: define #2
Working Stiffwork
A person sporting a woody at work.

Also, the action of working while having a stiffy.

I was working stiff this morning, bro. Still had a raging bone when I got to the office!