to cook (eggs, fish, fruits, etc.) in a hot liquid that is kept just below the boiling point.
Origin: 1350–1400; Middle English poche < Middle French pocher literally, to bag (the yolk inside the white), derivative of poche bag (French poche pocket) < Middle Dutch pokepoke2
"cook in liquid," c.1430, from O.Fr. poché, pp. of pochier (12c.), lit. "put into a pocket" (as the white of an egg forms a pocket for the yolk), from poche "bag, pocket," from Frank. *pokka "bag," from Gmc. *puk- (see poke (n.)).