A substance used for cleaning, a cleaning agent.
A professional laundry or dry cleaner (business). (This form is now interpreted as plural and usually spelled without an apostrophe, even in official usage, to justify the removal of the apostrophe. It was traditionally spelled cleaner's with an apostrophe because this is grammatically correct, as can be seen with forms such as go to the doctor's, which cannot be reinterpreted as plural.)
A person whose occupation is to clean floors, windows and other things.
A device that cleans, such as the vacuum cleaner.
A thing used to erase or remove something written or drawn by a pen or a pencil.
A thing used to erase something written by chalk on a chalkboard, by marker on a whiteboard, or by some other erasable implement; a chalkboard eraser, whiteboard eraser, etc.
One who erases.
An overwriter program used to prevent data recovery.