2. The inward impulses; the affections and passions; -- so
called because formerly supposed to have their seat in the
part of the body where the kidneys are.
My reins rejoice, when thy lips speak right things.
--Prov. xxiii.
16.
I am he which searcheth the reins and hearts. --Rev.
ii. 23.
{Reins of a vault} (Arch.), the parts between the crown and
the spring or abutment, including, and having especial
reference to, the loading or filling behind the shell of
the vault. The reins are to a vault nearly what the
haunches are to an arch, and when a vault gives way by
thrusting outward, it is because its reins are not
sufficiently filled up.