Английский Этимологический словарь - nest (n.)

- O.E. nest "bird's nest, snug retreat," from P.Gmc. *nistaz, from PIE *nizdo-, perhaps from *ni "down" + *sed- "sit." The verb is O.E. nistan, from P.Gmc. *nistijanan. Nest egg "retirement savings" is from 1700, originally "a real or artificial egg left in a nest to induce the hen to go on laying there" (1606).