Blackball

1. To vote against, by putting a black ball into a ballot box; to reject or exclude, as by voting against with black balls; to ostracize.
2. To blacken (leather, shoes, etc.) with blacking.
3. A composition for blacking shoes, boots, etc.; also, one for taking impressions of engraved work.
4. A ball of black color, esp. one used as a negative in voting; -- in this sense usually two words.