smear

an act that brings discredit to the person who does it

charge falsely or with malicious intent; attack the good name and reputation of someone

make a smudge on; soil by smudging

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

slanderous defamation

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

“smear the wall with paint”

stain by smearing or daubing with a dirty substance