What is "tailcoats"

Usage examples of "tailcoats".

At these reunions I had to play the part of host--to meet and entertain fat mercantile parvenus who were impossible by reason of their rudeness and braggadocio, colonels of various kinds, hungry authors, and journalistic hacks-- all of whom disported themselves in fashionable tailcoats and pale yellow gloves, and displayed such an aggregate of conceit and gasconade as would be unthinkable even in St.