spout off about (something)

Translations
разглагольствовать о (чём-то)
He always spouts off about politics at dinner parties.
Он всегда разглагольствует о политике на званых ужинах.
Definitions
To speak at length, often in a boastful, opinionated, or annoying way, about a particular topic, usually without being asked or without much consideration for others' interest or expertise.
Words
spout

verb
разглагольствовать
off

adverb
высказываться
about

preposition
о
something

pronoun
чём то