As has been characterized several times on this blog, Yiddish words and phrases as used in (American) English have a distinct role to play in uttertances with an emotive tinge. This aspect of lexicology and phraseology was brought to the fore of Y-H-B’s consciousness recently when he remembered that as an octogenarian he was approaching the status of an “alter kaker,” alias an “old geezer.” The difference between these two phrases is purely emotive to those speakers of American English who know both, and the nub of the difference is in the word kaker, which literally means ‘shit(-ter)’. The presence of the Yiddish profane verb root gives the phrase a pointedness that the translation lacks. Sic transit gloria mundi!
ADDENDUM: A better English equivalent for the Yiddish would be “old fart.”