n.
Pronunciation: ' gro ̇ in
Function: noun
Etymology: alteration of Middle English grynde, from Old English, abyss; akin to Old English grund ground
Date: circa 1532
1 : the fold or depression marking the juncture of the lower abdomen and the inner part of the thigh also : the region of this line
2 a : the projecting curved line along which two intersecting vaults meet b : a rib that covers this edge
3 : a rigid structure built out from a shore to protect the shore from erosion, to trap sand, or to direct a current for scouring a channel
groin 2a