A pat on the back is a light touch meaning well done. Give him a pat on the back, deserve a pat on the back.
It is also used to mean praise generally, so somebody can get a pat on the back in a letter. Giving yourself a pat on the back is the phrase's only mildly critical use.
1phrasepat on the backA light touch meaning well done.
“The whole team deserved a pat on the back for that month.”
pat on the back is a gesture.
Practised in Body Language & Gestures