girth vs perimeter

girth and perimeter both are nouns.

Word	Noun	Adjective	Verb	Adverb
girth	Yes	No	Yes	No
perimeter	Yes	No	No	No

As nouns, perimeter is a hypernym of girth; that is, perimeter is a word with a broader meaning than girth:

Other hypernyms of girth include circumference.

girth (noun)	perimeter (noun)
stable gear consisting of a band around a horse's belly that holds the saddle in place	the size of something as given by the distance around it
the distance around a person's body	the boundary line or the area immediately inside the boundary
	a line enclosing a plane areas

girth (verb)	perimeter (verb)
tie a cinch around