Explicit
early 17th century (as an adjective): from French explicite or Latin explicitus, past participle of explicare ‘unfold’ (see explicate).
wiktionary
First attested 1609, from French explicite, from Latin explicitus(“disentangled", "easy”), an alternative form of the past participle of explicāre(“to unfold”), from ex-(“out”) + plicō(“to fold”). Pornographic sense is from 1971.
etymonline
explicit (adj.)
1610s, "open to the understanding, not obscure or ambiguous," from French explicite, from Latin explicitus "unobstructed," variant past participle of explicare "unfold, unravel, explain," from ex "out" (see ex-) + plicare "to fold" (from PIE root *plek- "to plait").
As a euphemism for "pornographic" it dates from 1971 (phrases such as sexually explicit are earlier). Related: Explicitness. "Explicitus" was written at the end of medieval books, originally short for explicitus est liber "the book is unrolled."
