smudge

a dirty mark or smear.

a smeary state.

a stifling smoke.

a smoky fire, especially one made for driving away mosquitoes or safeguarding fruit trees from frost.

to mark with dirty streaks or smears.

to fill with smudge, as to drive away insects or protect fruit trees from frost.

to form a smudge on something.

to become smudged:

to smolder or smoke; emit smoke, as a smudge pot.