pontificate

Short definition from Wiktionary

Noun

1. 1
   The status or term of office of a pontiff or pontifex.

Verb

1. 1
   To preside as a bishop, especially at mass.
2. 2
   To act like a pontiff; to express one's position or opinions dogmatically and pompously as if they were absolutely correct.
3. 3
   To speak in a patronizing, supercilious or pompous manner, especially at length.