snob

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

• noun One who despises, ignores, or is patronizing to those he or she considers inferior.
• noun One who is convinced of his or her superiority in matters of taste or intellect.

from The Century Dictionary.

• noun A convulsive sob.
• noun Mucus of the nose.
• To sob or weep violently.
• noun A shoemaker; a journeyman shoemaker.
• noun A townsman as opposed to a gownsman; a Philistine.
• noun One who is servile in spirit or conduct toward those whom he considers his superiors, and correspondingly proud and insolent toward those whom he considers his inferiors; one who vulgarly apes gentility.
• noun A workman who continues working while others are out on strike; one who works for lower wages than other workmen; a knobstick; a rat: so called in abuse.

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

• noun A vulgar person who affects to be better, richer, or more fashionable, than he really is; a vulgar upstart; one who apes his superiors.
• noun (Eng. Univ.), Canf A townsman.
• noun Prov. Eng. A journeyman shoemaker.
• noun A workman who accepts lower than the usual wages, or who refuses to strike when his fellows do; a rat; a knobstick.

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

• noun disapproving, informal A person who seeks to be, or is, a member of the upper classes and looks down on lower classes, such as the middle class and the poor. More generally, an egotistical person who often thinks of people as inferior, particularly anyone not being within their clique or class.

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

• noun a person regarded as arrogant and annoying