pontificate on (something)
To speak about some issue in a particularly pompous, pretentious, or imperious manner. The principal lined us all up in the room and pontificated on the importance of hard work and discipline. It feels like we can't get through a single day in the office without my manager pontificating on how much better things were when she was first starting out in the industry.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
pontificate on something
to speak and act dogmatically and pompously. Must you pontificate on your own virtues so much? The speaker was pontificating on the virtues of a fat-free diet.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.