Pronunciation: (groin),[key] —n. 1. Anat.the fold or hollow on either side of the front of the body where the thigh joins the abdomen.
2. the general region of this fold or hollow.
3. Archit.the curved line or edge formed by the intersection of two vaults. See illus. under vault1.
4. Also,groyne.a small jetty extending from a shore to prevent beach erosion.