Akademik

fastener consisting of a resinous composition that is plastic when warm; used for sealing documents and parcels and letters

noun [noncount]

: a type of wax used especially in the past for making seals on letters and documents

ˈsealing wax [sealing wax sealing waxes] noun uncountable

a type of ↑wax that melts quickly when it is heated and becomes hard quickly when it cools, used in the past for ↑sealing letters, etc.