piece·meal 
(pēsmēl′)
(pēsmēl′)adv.
1. By a small amount at a time; in stages: articles acquired piecemeal.
2. In pieces; apart.
adj.
Accomplished or made in stages.
[Middle English pecemeale : pece, piece; see PIECE + -mele, by a fixed measure (from Old English -mǣlum, at a time, from dative pl. of mǣl, appointed time; see mē-2 in the Appendix of Indo-European roots).]