Don't 'smudge' the picture with your dirty hands!
Be careful not to 'smudge' [='smear'] the ink.
His hand left a grimy 'smudge' on the wall.
(..) Those marks on your forearm, edge of a desk. You've been typing in a hurry, probably, pressure on, facing a deadline. That all? There's an ink smudge on your wrist, a bulge in your jacket pocket. Bit of a giveaway? The smudge is deliberate, to see if I'm as good as they say I am. Hmm. Oil-based, (..)2012 TvShow: Sherlock Title: The Reichenbach Fall Season: 2 Episode 3