Shm- reduplication is a phenomenon whereby a word is duplicated, with the beginning of the word replaced by “shm-” (sometimes spelt “schm-”) the second time around, in order to convey scorn, skepticism or disinterest. A couple of examples from Wikipedia:
- “Baby-shmaby, he’s five years old!”
- “Sale, schmale, there’s nothing I’d want anyway.”
This construction came into American English from Yiddish, and from American English it has spread somewhat into other forms of English (at least, we recognise it). It’s also used in Modern Israeli Hebrew, with the same Yiddish origins.
Other languages have similar constructions, including a number in the Balkan sprachbund. For example, Turkish has reduplication with m-, but not with the sarcastic/dismissive meaning; there, it just means “and the like”, so for example kitap-mitap “books and such”. Bulgarian and Armenian also have m- reduplication (in Armenian it has the sarcastic connotation of Yiddish and English; I’m unclear on Bulgarian). Russian has both shm- and m- reduplication, also with the sarcastic meaning. It’s theorised that the Yiddish construction probably originally had a more neutral meaning like Turkish’s “and such”, but it was used flippantly so often that that became an inherent part of its meaning.