The Collaborative International Dictionary
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.
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.
Wiktionary
n. (context legal English) The part of the testator's will in which the residue of his/her estate is disposed of.
Usage examples of "residuary clause".
So that, if a devise of land should fail, that land would not be disposed of by the residuary clause, but would descend to the heir as if there had been no will.