During the 14th century, the gipon (or jupon) was first worn as a snug, knee-length, padded tunic beneath armour. Later, it was adapted to civilian use, and its length was shortened to mid-thigh. It was replaced by the doublet in the 15th and 16th centuries. It was sometimes called the pourpoint.
Origin:
1350–1400; ME jopo ( u ) n < MF jupon, equiv. to OF jupe a kindof jacket + -on n. suffix