a Dutch uncle

Dutch uncle

One who addresses someone severely or critically. Fred is always lecturing me like a Dutch uncle, forgetting the fact that I'm 40 years old!
See also: Dutch, uncle
Farlex Dictionary of Idioms.

a Dutch uncle

a kindly but authoritative figure.
Dutch here probably means no more than that the person described is not a genuine blood relation. In the mid 19th century I will talk to him like a Dutch uncle (meaning ‘I will give him a lecture’) was noted as being an American expression.
1999 Daily Telegraph She was the kindest of Dutch uncles, always prepared to listen to one's troubles.
See also: Dutch, uncle
Farlex Partner Idioms Dictionary
See also:
  • Dutch uncle
  • Dutch uncle, talk (to one) like a
  • an armchair critic
  • an armchair something
  • armchair
  • critic
  • lecture (one) for (something)
  • lecture for
  • armchair general
  • Uncle!