Rebuff comes from obsolete French rebuffer, from Italian ribuffare ('to reprimand'), from ri- (Latin re-) + buffo ('a puff, gust'), of imitative origin. The historical chain includes Italian ribuffare. The quoted older senses, "to reprimand" and "a puff, gust", supply the semantic anchors for rebuff. The formation is best read as compound and borrowed: the word rebuff carries its older form-history into a compact English lexical shape. In present English it is used as a verb, "to reject bluntly or snub". The result is a verb and noun whose etymology preserves both the older form and the later English specialization.