Noun

1. Slanderous defamation
2. A thin tissue or blood sample spread on a glass slide and stained for cytologic examination and diagnosis under a microscope
3. A blemish made by dirt
4. An act that brings discredit to the person who does it

Verb

1. Stain by smearing or daubing with a dirty substance
2. Make a smudge on; soil by smudging
3. Cover (a surface) by smearing (a substance) over it
4. Charge falsely or with malicious intent; attack the good name and reputation of someone