buttoned-up

Related to buttoned-up: buttoned down

buttoned-up

Very conservative, unimaginatively conventional, or old-fashioned, as of a person's clothing, attitude, behavior, or beliefs. He spent his entire adult life as a buttoned-up clerk, so, when he turned 65, he decided it was time for adventure.
Farlex Dictionary of Idioms.
See also:
  • behind (one's) time
  • behind time
  • fashion
  • good day
  • an old fogey/fogy
  • anon
  • a stuffed shirt
  • (Well,) I'll be durned!
  • a bit of crackling