Read the dictionary definition of pat. All definitions for this word.
1. a light touch or stroke
2. the sound made by a gentle blow
3. hit lightly
1. pat him on the shoulder
4. pat or squeeze fondly or playfully, especially under the chin
5. exactly suited to the occasion
1. a pat reply
6. having only superficial plausibility
1. glib promises
2. a slick commercial
7. completely or perfectly
1. he has the lesson pat
2. had the system down pat