Light touches (4)
'light touches' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for dabs that I've seen before include "Fingerprints (colloq.)" , "Applies light touches" , "Fish; fingerprints" , "fingerprint" , "Small quantities of liquid" .)
(Another definition for pats that I've seen is " Light touches or strokes".)