"one who asks alms," especially as a way of life, c. 1200, from Old French begart, "a member of the Beghards," a mendicant order of lay brothers in the Low Countries, from Middle Dutch beggaert "mendicant," a word of uncertain origin, with pejorative suffix (see -ard). The common noun is perhaps from the proper name; compare Beguine. Early folk etymology connected the English word with bag, but this is now dismissed (see OED).
From mid-14c. as "one who is indigent" (whether begging or not). From c. 1300 as "mean or low person;" as a familiar term for "a fellow, man" by 1833. Form with -ar attested from 14c., but begger was more usual 15c.-17c. The feminine form beggestere is attested as a surname from c. 1300. Beggar's velvet was an old name for "dust bunnies."