To put (one's signature), affix (a seal) to (†on) a document. (Cf. to set to at phrasal verbs 2.)

To affix (one's seal or signature). Obsolete.

transitive. To put one's signature or other identifying mark upon (a document), esp. at the end or foot, typically to signify consent or agreement…

transitive. To write (one's name or mark) on a document, esp. at the end or bottom, typically as a witness or consenting party; to sign (one's name)…

transitive and intransitive. To write one's signature or name (to); to indicate one's agreement or compliance (with); = subscribe, v. 1 2.

To affix, ‘sign’ (one's name) to a document or writing. Obsolete.

transitive. To write (one's name) as a signature. Also: to print a distinguishing mark representing (one's name).