from Latin magniloquus (of the same meaning), from magnus great
+ -loquus speaking + -ent
1656 - Glossographia, Thomas Blount;
"Magniloquent, that useth a stately manner of speaking or writeing"
From: Standard American Authors
Published under the Superintendence of Dr. Karl Elze,
Vol. IV, 1854
The Works of Henry W. Longfellow, Vol.I.
Kavanagh: A Tale, 1849. XXI