The Collaborative International Dictionary
Countersealing
Counterseal \Coun`ter*seal"\ (koun`t[~e]r*s[=e]l"), v. t. [imp.
& p. p. Countersealed (koun`t[~e]r*s[=e]ld"); p. pr. & vb.
n. Countersealing.]
To seal or ratify with another or others.
--Shak.
Wiktionary
countersealing
vb. (present participle of counterseal English)