NOUN (2)

1. minnows or other small fresh- or saltwater fish (especially herring); usually cooked whole;

2. the edible young of especially herrings and sprats and smelts;

The Collaborative International Dictionary of English v.0.48:

Whitebait \White"bait`\, n. (Zool.)
   (a) The young of several species of herrings, especially of
       the common herring, esteemed a great delicacy by epicures
       in England.
   (b) A small translucent fish (Salanx Chinensis) abundant at
       certain seasons on the coasts of China and Japan, and
       used in the same manner as the European whitebait.
       [1913 Webster]

WordNet (r) 3.0 (2006):

whitebait
    n 1: minnows or other small fresh- or saltwater fish (especially
         herring); usually cooked whole
    2: the edible young of especially herrings and sprats and smelts