1. A layer of phospholipid; thus, a bilayer has two leaflets. 2. A thin flattened object or structure.
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leaf·let 'lē-flət n a leaflike organ, structure, or part <lipid molecules in a bimolecular \leaflet> esp any of the flaps of the biscuspid valve or the tricuspid valve
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leaf·let (lēfґlət) 1. a small leaf or something resembling one. 2. cusp (def. 2).Medical dictionary. 2011.