backslap means to enthusiastically affirm or congratulate a person, especially by patting them on the back. Lexicurio rates it Sui generis — a strength score of 90 out of 100.
Etymology
From back + slap.
verb
- To enthusiastically affirm or congratulate a person, especially by patting them on the back.“In public he put on a performance that was at once outraged and outrageous, but usually he did not carry grudges into his private life. Exuding the backslapping air of a socializer who loved to gamble and drink, he could not understand why people whose careers he had ruined and publicly ridiculed would be hostile to his friendly advances.”