From Longman Dictionary of Contemporary Englishpat somebody/yourself on the backpat somebody/yourself on the backPRAISEto praise someone or yourself for doing something well You can pat yourselves on the back for a job well done. → pat
Examples from the Corpus
pat somebody/yourself on the back• Cliff Nudelman pats me on the back.• Every person on the street will pat you on the back.• For most of that ride it patted itself on the back.• The manager patted Stuart on the back.• This time I patted myself on the back all the way to the hotel.• She should pat herself on the back and take a well-earned break.• I patted him on the back as hard as I dared but he still couldn't breathe.• How dare she wave her bloody job at us like she wanted us to pat her on the back for it?• Because when I pat myself on the back, the next sensation is usually a sharp kick lower down. 