magniloquence (n.) Look up magniloquence at Dictionary.com
1620s, from Latin magniloquentia "elevated language, lofty style," from magniloquus "pompous in talk, vaunting, boastful," from comb. form of magnus "great" (from PIE root *meg- "great") + -loquus "speaking," from loqui "to speak" (from PIE root *tolkw- "to speak").