that part of the belly next the thigh.—In the Philosophical Transactions we have an account of a remarkable case, where a peg of wood was extracted from the groin of a young woman of 21, after it had remained 16 years in the stomach and intestines, having been accidentally swallowed when she was about five years of age. Vide Vol. LXVII. p. 459.

among builders, is the angular curve made by the intersection of two semi-cylinders or arches; and is either regular or irregular.—A regular groin is when the intersecting arches, whether semicircular or semieliptical, are of the same diameters and heights. An irregular groin is where one of the arches is semicircular and the other semieliptical.