1640s, "having the function of explaining," from Latin explicativus, from explicat-, past participle stem of explicare "unfold; explain," from ex "out" (see ex-) + plicare "to fold" (from PIE root *plek- "to plait"). As a noun, from 1775.
explanatory
expletive
explicable
explicate
explication
explicative
explicit
explicitly
explode
exploit
exploitation