Smear

slanderous defamation

a thin tissue or blood sample spread on a glass slide and stained for cytologic examination and diagnosis under a microscope

a blemish made by dirt

an act that brings discredit to the person who does it

stain by smearing or daubing with a dirty substance

make a smudge on

cover (a surface) by smearing (a substance) over it

charge falsely or with malicious intent