Gentle stroke; tap (3)
I believe the answer is:
pat
This clue is a double definition.
'gentle stroke' is the first definition.
(I've seen this before)
'tap' is the second definition.
(I know that tap can be written as pat)
(Other definitions for pat that I've seen before include "Light hand stroke" , "Conveniently; light touch" , "Slick; dab" , "Touch gently; glib" , "Glib; touch affectionately" .)