Water dog /(?)/

Wa·ter dog

Water dog
  1. A dog accustomed to the water, or trained to retrieve waterfowl. Retrievers, waters spaniels, and Newfoundland dogs are so trained. (Zool.)
  2. The menobranchus. (Zool.)
  3. A small floating cloud, supposed to indicate rain.
  4. A sailor, esp. an old sailor; an old salt. [Colloq.]