eraser eraser /ɪˈreɪ.zər/ aep /-ˈreɪ.sɚ/ noun [C] MAINLY US (UK USUALLYrubber) ► A1 a small piece of rubber used to remove the marks made by a pencil: » If you draw or write in pencil you can always rub out your mistakes with an eraser.Thesaurus+: ↑Writing implements