When in the 14th C? Over the 100 year period, fashions changed considerably. From what I've read, the surcoat (or surcotte) was going out of fashion in the earlier part of the century, changing to the cyclas, a close fitted garment that had a short front hem with knee length side and back hems. By the beginning of the third quarter of the century, jupons were all the rage for the well-dressed man-at-arms. At the close of the century, cloth covering for armor was almost completely abandoned.
Waffenrock (from wâfenroc or wâpenroc "weapon tunic") seems to be just the German name for the surcoat, although it was later used to refer to various German military uniforms until 1945.
