Green’s Dictionary of Slang

(US) an ordinary working citizen.

1968		T. Wolfe Electric Kool-Aid Acid test 309: He looks ten or fifteen years older, like an old workadaddy on the 21 -day plan to Mexico.
1970		A.D. Berton Social impact of Information Retrieval 3: But what are the services that the workadaddy husband and the PTA wife require from the giant brain?
1976		C. Dowling How to Love a Member of the Opposite Sex 59: I guess I wanted it both ways: a solemn, nine-to-five workadaddy and a gifted genius of a man.
1980		R. Jones Big Switch 287: [...] instead of a humdrum workadaddy, eternally faithful, except for a mean little skulking episode here and there.
1987		K. Kesey Demon Box 353: And all the while the father sat without comment, not moving, just the muscles in his forearms and his big workadaddy hands, gripping the back of the seat.
2009		J. Stahl Pain Killers 372: One workadaddy, waxing his pickup [...] threw down the rag and ran over.