How Well Do You Know English Slang?
"banal or excessive sentimentalism," 1935, from Yiddish shmalts, literally "melted fat," from Middle High German smalz, from Old High German smalz "animal fat," related to smelzan "to melt" (see smelt (v.)). Modern German Schmalz "fat, grease" has the same figurative meaning. First mentioned in English as "a derogatory term used to describe straight jazz" ["Vanity Fair," Nov. 1935].
Blatant sentimentality, esp musical or theatrical material of a cloyingly sweet and maudlin sort; corn: happy combination of good theater and good pathos known as schmaltz
[1935+ Swing musicians; fr Yiddish shmalts, literally ''rendered fat'']