I learnt this splendid word in an article about the eccentric English politician Jacob Rees-Mogg, who cultivates the air of an outdated aristocrat who has barely reached the 19th century, let alone the 21st. It means the habit of giving opinions and advice on matters outside of one’s knowledge. https://en.m.wikipedia.org/wiki/Ultracrepidarianism
The man himself would be proud to use it.
Made me laugh of your description of Jacob Rees-Mogg.