Pompensate

[pom-puhn-seyt]
Pompous + Compensate
verb

1. to attempt to mask one's inadequacies by acting knowledgeable or cool but instead appearing as a pompous @$$hole.

Ex. "Gil's been pompensating all night; his never-ending rant about the lacking supply of well-patterned pocketsquares on the island of Manhattan was quite obviously meant to distract us from staring at his weak chin. And you don't even want to know what he had to say about the canapés."