"alluringly plump, curvaceous, buxom," 1937, from Yiddish zaftik, literally "juicy," from zaft "juice," from Middle High German saft "juice" (see sap (n.1)).
Entries linking to zaftig
sap n.1
"juice or fluid which circulates in plants, the blood of plant life," Middle English sap, from Old English sæp, from Proto-Germanic *sapam (source also of Middle Low German, Middle Dutch, Dutch sap, Old High German saf, and, with unetymological -t, German Saft "juice"). This is reconstructed to be from PIE root *sab- "juice, fluid" (source also of Sanskrit sabar- "sap, milk, nectar," Irish sug, Russian soku "sap," Lithuanian sakas "tree-gum"). As a verb meaning "to drain the sap from," by 1725.