Yoke: Usually found on the oxford shirts or western wear, this small panel of fabric that comes from the shoulder and down several inches, often decorative. It may be a part of the front as well, coming from the shoulders to the chest/pocket level of the shirt.
Zipper: Closure device for clothing and accessories which incldes interlocking theeth that open and close by coming together/interlociking when engaged by pulling up or down a zipper pull.
ZigZag: The stitch that goes one way zig and then the other way zag and provides a nice finish to a seam to help prevent raveling and can be a decorative addition to any garment.
