loquacious adj.

c. 1200, from Latin loquacitatem (nominative loquacitas) "talkativeness," from loquax "talkative," from loqui "to speak" (from PIE root *tolkw- "to speak"). An Old English word for it was ofersprecolnes. Compare French loquacité, Spanish locuacidad, Italian loquacità.

Proto-Indo-European root meaning "to speak."

It forms all or part of: circumlocution; colloquium; colloquy; elocution; eloquence; grandiloquence; interlocution; interlocutor; locution; locutory; loquacious; loquacity; loquitur; magniloquence; magniloquent; obloquy; soliloquy; somniloquy; vaniloquence; ventriloquism; ventriloquy.

It is the hypothetical source of/evidence for its existence is provided by: Latin loqui "to speak;" Old Irish ad-tluch- "to thank," to-tluch- "to ask;" Old Church Slavonic tloko "interpretation, explanation."

word-forming element making adjectives from nouns, meaning "having, full of, having to do with, doing, inclined to," from Old French -ous, -eux, from Latin -osus (compare -ose (1)). In chemistry, "having a lower valence than forms expressed in -ic."