An ornamental pin for holding a tie in place.Men were given the choice of a tiepin or lapel badge....
It's really aggravating, but I don't want to wear a tiepin and look like a total geek either.
However, more modish philosophical gentlemen of the period looked quite different, usually sporting a fashionably ‘lank’ hairstyle, a shortened form of frock coat, and a stock fastened with a tiepin.