As verbs the difference between grip and girth
is that
grip is to take hold of, particularly with the hand while
girth is to bind as if with a girth or band.
As nouns the difference between grip and girth
is that
grip is a hold or way of holding, particularly with the hand or
grip can be (dialectal) a small ditch or trench; a channel to carry off water or other liquid; a drain or
grip can be (obsolete) the griffin while
girth is the distance measured around an object.