The adjective cavalier comes from
a noun referring to a gentleman or knight who is trained in arms and
horsemanship. The noun traces back to Latin caballārius, meaning
"horseback rider" or "groom." It is also used for "a
swaggering fellow," and English Puritans used it disdainfully to their
adversaries, the swashbuckling royalist followers of Charles I, who sported
longish hair and swords. Their use undoubtedly contributed to the adjective's
reference to a rather unbecoming quality.
