The<unk>  or<unk>  (pl.) (), is the crescent-shaped whitish area of the bed of a fingernail or toenail. In humans, it appears by week 14 of gestation, and has a primary structural role in defining the free edge of the distal nail plate (the part of the nail that grows outward).
Lunula 
Microgyrus
Syrinx 
Tophus
Gyrus
Ranula
Collateral eminence
Oral torus