Meaning of “rubber” - Learner’s Dictionary

rubber

noun uk us /ˈrʌbər/
SUBSTANCE [ U ]

B2 a strong material that bends easily, originally produced from the juice of a tropical tree, and used to make tyres, boots, etc

PENCIL [ C ] UK (US eraser)

A2 a small object that is used to remove pencil marks from paper

(Definition of “rubber” from the Cambridge Learner’s Dictionary © Cambridge University Press)