From Longman Dictionary of Contemporary Englishemery boardˈemery board noun [countable] DCBa narrow piece of stiff paper with emery on it, used for shaping your nails
Examples from the Corpus
emery board• Keep an emery board handy in case of nail snags, so your teeth do not get to them first!• It grated like an emery board on my nails.• Use an emery board to smooth sharp edges that could cut an adjacent toe.• Smooth over the edges with an emery board.• When filing, use a disposable emery board as opposed to a metal file. 