[uhn-der-sahyn, uhn-der-sahyn]
See more synonyms for undersign on Thesaurus.com

Origin of undersign

First recorded in 1570–80; under- + sign
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Word Origin and History for undersign

1570s, from under + sign (v.). Related: Undersigned; undersigning.

Online Etymology Dictionary, © 2010 Douglas Harper