The Collaborative International Dictionary of English v.0.48:
Ringneck \Ring"neck`\, n.
1. (Zool.) Any one of several species of small plovers of the
genus Aegialitis, having a ring around the neck. The
ring is black in summer, but becomes brown or gray in
winter. The semipalmated plover (Aegialitis semipalmata)
and the piping plover (Aegialitis meloda) are common
North American species. Called also ring plover, and
2. (Zool.) The ring-necked duck.