Wiktionary
suit and tie
a. Describable as formal, serious, and professional
Usage examples of "suit and tie".
Out of his suit and tie, he looked like another person, the sweatshirt emblazoned with the Howlers’.
Barty Crouch was a stiff, upright, elderly man, dressed in an impeccably crisp suit and tie.
He was wearing his suit and tie again, seeing he was calling on a lady.
There was a pretty young woman in a fashionable dress and a small man attired, as he was, in a conventional suit and tie.
Out the jetway, between two ordinary civilians who probably thought him a businessman, with his suit and tie.