As nouns the difference between loin and frank
is that
loin is the part of the body (of humans and quadrupeds) at each side of the backbone, between the ribs and hips while
frank is free postage, a right exercised by governments (usually with definite article).
As an adjective frank is
honest, especially in an manner that seems slightly blunt; candid; not reserved or disguised.
As a verb frank is
to place a frank on an envelope.
As a proper noun Frank is
a given name derived from Germanic.