v. & n.
v. (patted, patting) 1 tr. strike gently with the hand or a flat surface. 2 tr. flatten or mould by patting. 3 tr. strike gently with the inner surface of the hand, esp. as a sign of affection, sympathy, or congratulation. 4 intr. (foll. by on, upon) beat lightly.
n. 1 a light stroke or tap, esp. with the hand in affection etc. 2 the sound made by this. 3 a small mass (esp. of butter) formed by patting. pat-a-cake a child's game with the patting of hands (the first words of a nursery rhyme). pat on the back a gesture of approval or congratulation. pat a person on the back congratulate a person.
[ ME, prob. imit. ]