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"), from the same source as Old English gyrdan "to gird" (see gird). 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.

"encircle with a girdle," 1580s, from girdle, n.. Meaning "to cut off a belt of bark around a trunk to kill a tree" is from 1660s, especially in North America. Related: Girdled; girdling.