wiper

noun

1. a person or thing that wipes
2. something used for wiping, as a towel or rag
3. a moving electrical contact, as in a rheostat
4. a projecting piece on a rotating or rocking part, which raises and lowers or trips another, usually reciprocating, part; cam; eccentric
5. a squeegee blade attached to an arm that can be moved automatically back and forth across a windshield