busker (n.)
"itinerant entertainer," 1857, from busk (v.) "to offer goods for sale only in bars and taprooms," 1851 (in Mayhew), perhaps from busk "to cruise as a pirate," which was used in a figurative sense by 1841, in reference to people living shiftless and peripatetic lives. Busker has been mistakenly derived from buskin in the stage sense.