The whitish, half-moon shape at the base of the nail is called the:

The lunula is the whitish, half-moon-shaped area visible at the base of the natural nail. It is actually the part of the matrix (the nail's growth center) showing through the nail plate. The free edge is the part of the nail that extends past the fingertip, the nail bed is the skin beneath the nail plate, and the cuticle is the dead skin overlapping the nail base. Identifying the parts of the nail unit by their correct names, including the lunula, is core nail science on the exam.