cavalier

Lacking the proper care or concern for something important, reckless, rash, high-handed.

But, on the following day, no sign of Poirot. I was getting angry. He was really treating us in the most cavalier fashion.

Such a cavalier attitude might seem to suggest that doctors consider the uterus as dispensable an organ as, say, an appendix—and some feminists have accused the medical profession of just such callousness […]

High-spirited.

Supercilious.

Free and easy; unconcerned with formalities

Leporello (a surname that proved the antechamber not to be wholly illiterate), far from resembling Don Juan’s trembling valet, was a handsome young man, with an animated face, nimble in gait, and of cavalier manners; wearing elegantly enough the clothes which had, doubtless, appertained to his master; and evidently quite the pet of the ladies present, and paying assiduous court to Mademoiselle Astarté, the queen of the party.

Of or pertaining to the party of King Charles I of England (1600–1649).

A military man serving on horse, (chiefly) early modern cavalry officers who had abandoned the heavy armor of medieval knights.

A gallant: a sprightly young dashing military man.

A gentleman of the class of such officers, particularly

A gentleman of the class of such officers

Someone with an uncircumcised penis.

The roundheads in the school showers easily equalled the cavaliers.

Since penile preference is so tied up with personal aesthetics and body image, it seems both logical and fair to leave the choice of cavalier or roundhead to the owner of the organ, thus avoiding the sort of life-long pain expressed in a comment like this:[…]

Of a man: to act in a gallant and dashing manner toward (women).

His social and kind nature is inferred from his cavaliering the ladies Percy and Mortimer, and introducing them, before their husbands depart for the war.

"I thought," Graeme burred at him, transfixing him with shrewd eyes, "that you were cavaliering the Italian girl, Beatrice Cenci or Vittoria Colonna or whatever her name is?"