Doublet
dub'let, a form of outer garment worn by men during the latter part of the fifteenth century. Originally the doublet had long skirts and was held in place by a belt. Later it was of shorter cut, was fitted with great nicety, and padded, if necessary, to the correct shape. After the time of Charles I, in England the doublet was made without sleeves, and a coat was worn over it. It is supposed that the present fashion of the waistcoat or vest was developed from the doublet.
Volume II · Aiton’s Encyclopedia