eponychium

noun

ep·​o·​nych·​i·​um ˌep-ə-ˈnik-ē-əm 

1

: the thickened layer of epidermal tissue over the developing fetal fingernail or toenail that disappears before birth except over the base of the nail

2

: the distal margin of the superficial layer of a proximal nail fold that is a horny band of epidermis extending over the base of a nail : cuticle