cavalier

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A gallant or chivalrous man, especially one serving as escort to a woman of high social position; a gentleman.
• noun A mounted soldier; a knight.
• noun A supporter of Charles I of England in his struggles against Parliament.
• adjective Showing arrogant or offhand disregard; dismissive.
• adjective Carefree and nonchalant; jaunty.
• adjective Of or relating to a group of 17th-century English poets associated with the court of Charles I.

from The Century Dictionary.

• To act as a cavalier; ape the manners of a cavalier; carry one's self in a disdainful or high-handed fashion: sometimes followed by it: as, to try to cavalier it over one's associates.
• noun A horseman, especially an armed horseman; a knight.
• noun One who has the spirit or bearing of a knight; especially, a bold, reckless, and gay fellow.
• noun [capitalized] The appellation given to the partizans of Charles I. of England in his contest with Parliament.
• noun During some years they were designated as Cavaliers and Roundheads. They were subsequently called Tories and Whigs.
• noun A man attending on or escorting a woman, or acting as her partner in dancing; a gallant; a beau.
• noun In medieval fortification, a mound defended by walls and the like, raised so as to command the neighboring ramparts; hence, in modern fort., a raised work commonly situated within the bastion, but sometimes placed in the gorges, or on the middle of the curtain.
• noun In the manège, one who understands horse-manship; a skilled or practised rider.
• Knightly; brave; warlike.
• Gay; sprightly; easy; offhand; frank; careless.
• Haughty; disdainful; supercilious: as, a rude and cavalier answer.
• [capitalized] Belonging or relating to the party of Charles I. of England.

from the GNU version of the Collaborative International Dictionary of English.

• noun A military man serving on horseback; a knight.
• noun A gay, sprightly, military man; hence, a gallant.
• noun One of the court party in the time of king Charles I. as contrasted with a Roundhead or an adherent of Parliament.
• noun (Fort.) A work of more than ordinary height, rising from the level ground of a bastion, etc., and overlooking surrounding parts.
• adjective offhand; unceremonious; gay; easy; frank. Opposed to serious.
• adjective obsolete High-spirited.
• adjective Supercilious; haughty; disdainful; curt; brusque.
• adjective Of or pertaining to the party of King Charles I.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Not caring enough about something important.
• adjective High-spirited.
• adjective Supercilious; haughty; disdainful; curt; brusque.
• adjective Of or pertaining to the party of King Charles I.
• noun A military man serving on horse.
• noun A sprightly, military man; hence, a gallant.
• noun One of the court party in the time of King Charles I, as contrasted with a Roundhead or an adherent of Parliament.
• noun A work of more than ordinary height, rising from the level ground of a bastion, etc., and overlooking surrounding parts.
• noun A well mannered man; a gentleman.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a royalist supporter of Charles I during the English Civil War
• adjective given to haughty disregard of others
• noun a gallant or courtly gentleman