mouth glue
/ˈmaʊθ ɡluː/Now historical and rare
noun
A compound of glue and sugar, originally a preparation of isinglass, which becomes adhesive when moistened (typically with the tongue). Also (occasionally): †= isinglass ( obsolete ).
Origin
Late 16th century; earliest use found in John Baret (d. 1578), lexicographer. From mouth + glue.