UNDERSIGNED
Etymology
Adjective
undersigned (comparative more undersigned, superlative most undersigned)
(of a document) having signatures at the end or bottom
(of a person) having signed at the end of a document
Noun
undersigned (plural undersigneds or undersigned)
the person or those people, mentioned in a document, whose names and signatures appear at the end
Usage notes
Sometimes used by authors to refer to themselves in contexts in which first-person pronouns are conventionally not or not usually used, e.g. court decisions.
Source: Wiktionary
UNDERSIGN
Un`der*sign", v. t.
Definition: To write one's name at the foot or end of, as a letter or any
legal instrument. The undersigned, the person whose name is signed,
or the persons whose names are signed, at the end of a document; the
subscriber or subscribers.
Source: Webster’s Unabridged Dictionary 1913 Edition