What Is A Palooka?
The Short Answer
A palooka is a clumsy, second-rate prizefighter: big, slow, easy to hit and easy to beat. By extension it's any large man who isn't too bright. It was an insult at ringside first and a fond one later.
When The Word Appeared
The Oxford English Dictionary gives its earliest evidence as 1920 and its origin as unknown.
Green's Dictionary of Slang quotes the sportswriter Damon Runyon in April 1923 calling palooka a new word, much used lately, for what had been called a set-up, a sucker or a pushover. A Nebraska paper used it the month before about a man built up by press agents to fight Jack Dempsey. By 1926 The Ring was defining it for its readers as a tenth rater.
So the word belongs to the first years of the 1920s. That's the decade Mickey Palooka is set in, and his name is an old joke that was new then.
Where It Came From
Nobody knows. Oxford, American Heritage and Etymonline all say origin unknown.
It's often credited to Jack Conway, a writer at Variety. That credit traces to a magazine piece printed in 1936, 8 years after Conway died, and no dictionary shows the word in anything he wrote. He may have made it popular. There's no evidence that he coined it.
You'll also read that it comes from a Polish surname or from an Italian word for a straw man. Those are guesses, and no dictionary endorses either one.
The Comic Strip Came Later
A well known newspaper comic strip about a good-natured heavyweight began in April 1930, a decade after the word was first in print. The strip spread the word and softened it, until a palooka could be any ordinary guy. It did not invent it.
What 1920 Called Him Instead
Before palooka caught on, the same fighter was a ham and egger, a set-up or a pushover. Tomato can, which sounds older, isn't recorded until 1977.
In The Game
You don't play Mickey Palooka. He's the last man who signed a marker with Abe Saltz and never paid, and the wires bring him up every week. You sign your own name.