Smear (optics) definition

(1) An act that brings discredit to the person who does it

"He made a huge blot on his copybook"

(2) A blemish made by dirt

"He had a smudge on his cheek"

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

(4) Slanderous defamation

(5) Charge falsely or with malicious intent; attack the good name and reputation of someone

"The journalists have defamed me!" "The article in the paper sullied my reputation"

(6) Cover (a surface) by smearing (a substance) over it

"Smear the wall with paint"

"Daub the ceiling with plaster"

(7) Make a smudge on; soil by smudging

(8) Stain by smearing or daubing with a dirty substance