smear

To spread (a substance, especially one that colours or is dirty) across a surface by rubbing.

The artist smeared paint over the canvas in broad strokes.

In general, all bodies whose surfaces are even will […] stick to each other, and if a liquid be smeared over either surface, their cohesion will be still the stronger.

To cover (a surface with a layer of some substance) by rubbing.

She smeared her lips with lipstick.

Why did you bring these daggers from the place? They must lie there: go carry them; and smear The sleepy grooms with blood.

To make something dirty.

A man may bee smeared or grimed, and euerie man shall laugh at him, and yet he himselfe shall not perceiue it a whit.

[…] she returned, carrying Johnnie, his face all smeared with eating,

(of a substance, etc.) To make a surface dirty by covering it.

a pallor which was accentuated by the blood which smeared her lips and cheeks and chin

a rust spot smearing the back of the sink

To damage someone's reputation by slandering, misrepresenting, or otherwise making false accusations about them, their statements, or their actions.

The opposition party attempted to smear the candidate by spreading incorrect and unverifiable rumors about their personal behavior.

May everlasting shame consume The memory of those who tried To befoul and smear th’ exalted name Of one who spurned them in his pride.

A mark made by smearing.

This detergent cleans windows without leaving smears.

A smear of decisive lead-coloured paint had been laid on to obliterate Henchard’s name, though its letters dimly loomed through like ships in a fog.

A false or unsupported, malicious statement intended to injure a person's reputation.

smear campaign

I should have held him quite beneath my Notice, as is all he utters, but that the Appetite of Slander, in many, is too predominant; and, ’tis possible, when the filthiest Fellow throws a Profusion of Dirt, some may chance to stick, if not timely thrown off; I shall endeavour therefore, to wipe away the sooty Smears of this Chimney-sweeper, by relating a simple Fact, which will, I flatter myself, amply confute the malicious Tales of this unprovoked, rancorous Mortal:

A preparation to be examined under a microscope, made by spreading a thin layer of a substance (such as blood, bacterial culture) on a slide.

A Pap smear (screening test for cervical cancer).

I'm going to the doctor's this afternoon for a smear.

Any of various forms of distortion that make a signal harder to see or hear.

In television terms, a certain amount of smear, ringing, and anticipatory overshoot are indigenous to VSB transmission.

Results show the reduction in intelligibility produced by changing the filter condition was much greater than reductions caused by altering smear duration.