groin
n. countablen. the area where your legs meet the rest of your body. In buildings, it can also mean the curved line where two arched ceilings cross each other.
n. the fold or hollow on either side of the human body where the thigh joins the abdomen; also refers to the curved edge formed by the intersection of two vaults in architecture.
He pulled a muscle in his groin while playing soccer.
The athlete underwent surgery to repair a persistent groin injury that had sidelined him for the entire season.
The cathedral's ceiling features intricate stone groins that distribute the weight of the roof while creating a striking visual pattern for those looking up from the nave.
From earlier grine, from Middle English grinde, grynde, from Old English grynde (“abyss”) (perhaps also "depression, hollow"), probably related to Proto-Germanic *grunduz; see ground. Later altered under the influence of loin.
From Middle English groynen, from a mixture of Old French groignier, grougnier (from Latin grunniō) and Old English grunnian (from Proto-Germanic *grunnōną).
In its anatomical sense, it is often used with 'pull' or 'strain' to describe sports injuries.