Word Origin & History
O.E. flocc "a group of persons," related to O.N. flokkr "crowd, troop, band," M.L.G. vlocke "crowd, flock;" not found in other Gmc. languages, perhaps related to folc "people," but the metathesis would have been unusual for O.E. Extended c.1200 to "a number of animals of one kind moving or feeding together;"
of domestic animals c.1300. Transferred to bodies of Christians, in relation to Christ or their local pastor, from mid-14c. The verb meaning "to gather, congregate" is from c.1300. Related: Flocked; flocking.