"life of idle begging," 1706, from vagrant + abstract noun suffix -cy. Earlier in a figurative sense, "mental wandering" (1640s). By late 18c. used in law as a catch-all for miscellaneous petty offenses against public order.
vagina
vaginal
vaginismus
vaginitis
vagitus
vagrancy
vagrant
vague
vaguely
vagus
vail