girth n.

Old English gyrdel "belt, sash, cord drawn about the waist and fastened," worn by both men and women, common Germanic (cognates: Old Norse gyrðill, Swedish gördel, Old Frisian gerdel, Dutch gordel, Old High German gurtil, German Gürtel "belt"), related to Old English gyrdan "to gird," from PIE root *gher- (1) "to grasp, enclose" with instrumental suffix -el (1). Modern euphemistic sense of "elastic corset not extending above the waist" first recorded 1925. Originally a belt to secure the clothes, also for carrying a purse, a weapon, keys, etc.

Old English gyrdan "put a belt or girdle around; encircle; bind with flexible material; invest with attributes," from Proto-Germanic *gurdjan (source also of Old Norse gyrða, Old Saxon gurdian, Old Frisian gerda, Dutch gorden, Old High German gurtan, German gürten), from PIE *ghr-dh-, suffixed form of root *gher- (1) "to grasp, enclose." Related: Girded; girding.

Throughout its whole history the English word is chiefly employed in rhetorical language, in many instances with more or less direct allusion to biblical passages. [OED]

As in to gird oneself "tighten the belt and tuck up loose garments to free the body in preparation for a task or journey."

Proto-Indo-European root meaning "to grasp, enclose."

It forms all or part of: Asgard; carol; choir; choral; chorale; choric; chorister; chorus; cohort; cortege; court; courteous; courtesan; courtesy; courtier; curtilage; curtsy; garden; garth; gird; girdle; girt; girth; -grad; hangar; Hilda; Hildegard; Hortense; horticulture; jardiniere; kindergarten; Midgard; orchard; Terpsichore; Utgard; yard (n.1) "patch of ground around a house."

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit ghra- "house;" Albanian garth "hedge;" Greek khortos "pasture;" Phrygian -gordum "town;" Latin hortus "garden;" Old Irish gort "field," Breton garz "enclosure, garden;" Old English gyrdan "to gird," geard "fenced enclosure, garden," German Garten "garden." Lithuanian gardas "pen, enclosure," Old Church Slavonic gradu "town, city," and Russian gorod, -grad "town, city" belong to this group, but linguists dispute whether they are independent developments or borrowings from Germanic.