1876, originally in linguistics, probably from implode on the model of explosive; implosive is attested in French and German from 1860s.
Entries linking to implosive
implode v.
1870 (implied in imploded), back-formation from implosion. Related: Imploding.
explosive adj.
1660s, "tending to explode," from Latin explos-, past participle stem of explodere "drive out, reject" (see explosion) + -ive. As a noun, from 1874. Related: Explosives (n.); explosively; explosiveness.