The Collaborative International Dictionary
to duke it out
duke \duke\ (d[=u]k) v. t. To beat with the fists. [slang]
to duke it out to fight; -- usually implying, to fight with the fists; to settle a dispute by fighting with the fists. See duke, n. sense 4.
Usage examples of "to duke it out".
Who wants to duke it out with a dead Loghyr who's had several thousand years to practice being nasty?
First, a power-drunk warlock had appeared out of nowhere, and I had to duke it out with him in his own stronghold before he murdered me outright.