\Ring"-necked`\, a. (Zo["o]l.)
Having a well defined ring of color around the neck.
{Ring-necked duck} (Zool.), an American scaup duck ({Aythya
   collaris}). The head, neck, and breast of the adult male
   are black, and a narrow, but conspicuous, red ring
   encircles the neck. This ring is absent in the female.
   Called also {ring-neck}, {ring-necked blackhead},
   {ringbill}, {tufted duck}, and {black jack}.