—n.
1 the distance around a thing.
2 a band round the body of a horse to secure the saddle etc.
—v.
1 tr. a secure (a saddle etc.) with a girth. b put a girth on (a horse).
2 tr. surround, encircle.
3 intr. measure (an amount) in girth.
Etymology: ME f. ON gjoumlrth, Goth. gairda f. Gmc
Useful english dictionary. 2012.