groin

[groin] /grɔɪn/
noun
1.
Anatomy. 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.
Architecture. the curved line or edge formed by the intersection of two vaults.
4.
Also, groyne. a small jetty extending from a shore to prevent beach erosion.
verb (used with object)
5.
Architecture. to form with groins.
Origin
1350-1400; earlier grine, Middle English grinde; compare Old English grynde abyss, akin to grund bottom, ground1
Related forms
ungroined, adjective
British Dictionary definitions for groin

groin

/ɡrɔɪn/
noun
1.
the depression or fold where the legs join the abdomen related adjective inguinal
2.
(euphemistic) the genitals, esp the testicles
3.
a variant spelling (esp US) of groyne
4.
(architect) a curved arris formed where two intersecting vaults meet
verb
5.
(transitive) (architect) to provide or construct with groins
Word Origin
C15: perhaps from English grynde abyss; related to ground1

groyne

/ɡrɔɪn/
noun
1.
a wall or jetty built out from a riverbank or seashore to control erosion Also called spur, breakwater
Word Origin
C16: origin uncertain: perhaps altered from groin
Word Origin and History for groin
n.

1590s, earlier grine (1530s), from Middle English grynde "groin" (c.1400), originally "depression in the ground," from Old English grynde "abyss," perhaps also "depression, hollow," from Proto-Germanic *grundus (see ground). Altered 16c. by influence of loin or obsolete groin "snout." The architectural groin "edge formed by the intersection of two vaults" is from 1725.

groin in Medicine

groin (groin)
n.
The crease or hollow at the junction of the inner part of each thigh with the trunk, together with the adjacent region and often including the external genitals.