perorate

perorate \PUR-uh-rayt\, intransitive verb:

1. To conclude or sum up a long discourse.
2. To speak or expound at length; to declaim.

These people don't talk, they perorate, pontificate, bombast.
-- Jean Charbonneau, "Biographer's quest becomes self-searching journey", Denver Post, January 28, 2001

Our mother favored a staccato, stand-up style; if our father could perorate, she could condense.
-- Annie Dillard, "The Leg In The Christmas Stocking: What We Learned From Jokes", New York Times, December 7, 1986

You may perorate endlessly.
-- Richard Elman, "A Rap on Race", New York Times, June 27, 1971

Perorate comes from Latin perorare "to speak at length or to the end," from per-, "through, throughout," + orare, "to speak."