a person who imitates, cultivates, or slavishly admires social superiors and is condescending or overbearing to others.
a person who believes himself or herself an expert or connoisseur in a given field and is condescending toward or disdainful of those who hold other opinions or have different tastes regarding this field:
a musical snob.
1775-85; orig. uncert; first used as a nickname for a cobbler or cobbler's apprentice, hence a townsman, someone of low class or lacking good breeding, commoner, hence someone who imitates persons of higher rank
1781, "a shoemaker, a shoemaker's apprentice," of unknown origin. It came to be used in Cambridge University slang c.1796 for "townsman, local merchant," and by 1831 it was being used for "person of the ordinary or lower classes." Meaning "person who vulgarly apes his social superiors" arose 1843, popularized 1848 by William Thackeray's "Book of Snobs." The meaning later broadened to include those who insist on their gentility, in addition to those who merely aspire to it, and by 1911 had its main modern sense of "one who despises those considered inferior in rank, attainment, or taste."