backslapper

Noun

 * 1) One who makes a show of liking another person with profuse or excessive displays of camaraderie, such as vigorous hand clasping, back-slapping, hearty words of greeting, etc.

Usage notes
Often used at least mildly pejoratively.

Synonyms

 * (always pejorative)

Translations

 * Icelandic: axlaklappari, mjög viðkunnanlegur maður (of a man), mjög viðkunnanleg kona  (of a woman); yfirmáta kumpánalegur maður  (of a man), yfirmáta kumpánaleg kona  (of a woman)
 * Swedish: ryggdunkare