piecemeal (adv.)

"by pieces, in pieces, piece by piece, bit by bit," c. 1300, pece-mele, from piece (n.1) + Middle English meal "fixed time, period of time, occasion," from Old English mælum "at a time," dative plural of mæl "appointed time, food served" (see meal (n.1)). The second element once was more common, as in Old English styccemælum "bit by bit." Compare gearmælum "year by year," and inchmeal.