Short form of Curtis or Conrad; from Old French 'curteis' meaning 'courteous, polite'.
Curt most often arrives as the shortened form of Curtis, which derives from the Old French curteis — courteous, refined, of polished manners. That origin is pleasantly at odds with what the name sounds like today: clipped, brisk, no-nonsense. The evolution from courtly refinement to sharp brevity is itself a small story about how names drift free of their etymologies.
Curt also overlaps with Kurt, the German and Scandinavian form of Konrad (Old High German, bold counsel), which became anglicized in American usage until the two variants were nearly interchangeable. Curt Flood stands as one of the name's most consequential bearers — the St. Louis Cardinals center fielder who in 1969 refused a trade and challenged baseball's reserve clause all the way to the Supreme Court.
Flood lost the case but cracked open the door that led to free agency, fundamentally restructuring professional sports economics. His sacrifice of his career for a principle he would not personally benefit from gave the name a dimension of principled stubbornness that suits its sound perfectly. Curt Schilling's blood-soaked sock in the 2004 ALCS added another chapter of athletic lore.
As a standalone given name, Curt peaked in the mid-20th century and has since retreated to relative rarity, which gives it the same clean vintage quality as other four-letter mid-century names. It asks for no embellishment. What you see is exactly what you get.