countersignature

[ koun-ter-sig-nuh-cher ]
/ ˌkaʊn tərˈsɪg nə tʃər /

noun

a signature added by way of countersigning.

Origin of countersignature

First recorded in 1835–45; counter(sign) + signature
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for counter-signature