Definition from Wiktionary, the free dictionary
See also Sander
sander (plural sanders)
- A person employed to sand wood.
- A machine to mechanize the process of sanding.
- (railway) A device which spreads sand in snowy or icy conditions to improve traction.
- (archaic) Previously a small device resembling a saltshaker but containing sand that was shaken over a document to remove excess ink.
Derived terms 
machine for sanding
archaic: device to remove excess ink