noun
emery board
A nail file made of emery paper, used for shaping and smoothing nails.
エメリーボードで爪の形を整える。
I shape my nails with an emery board.
爪やすり is the general Japanese term for 'nail file', while エメリーボード specifically refers to an emery board, a type of nail file with a cardboard or wooden core coated with emery.
Loanword from English 'emery board'.