n. 大言不惭, 夸张, 做作

[ noun ]
high-flown style; excessive use of verbal ornamentation
<noun.communication>
the grandiosity of his prosean excessive ornateness of language

Grandiloquence \Gran*dil"o*quence\, n.
The use of lofty words or phrases; bombast; -- usually in a
bad sense.

The sin of grandiloquence or tall talking. --Thackeray,