The Collaborative International Dictionary of English v.0.48:
Residuary \Re*sid"u*a*ry\ (-?-r?), a. [See Residue.]
Consisting of residue; as, residuary matter; pertaining to
the residue, or part remaining; as, the residuary advantage
of an estate. --Ayliffe.
[1913 Webster]
Residuary clause (Law), that part of the testator's will in
which the residue of his estate is disposed of.
Residuary devise (Law), the person to whom the residue of
real estate is devised by a will.
Residuary legatee (Law), the person to whom the residue of
personal estate is bequeathed.
[1913 Webster]