Easton's Bible Dictionary (1897)/Ephod
Ephod: something girt, a sacred vestment worn originally by the high priest (Exodus 28:4), afterwards by the ordinary priest (1 Samuel 22:18), and characteristic of his office (1 Samuel 2:18,28; 14:3). It was worn by Samuel, and also by David (2 Samuel 6:14). It was made of fine linen, and consisted of two pieces, which hung from the neck, and covered both the back and front, above the tunic and outer garment (Exodus 28:31). That of the high priest was embroidered with divers colours. The two pieces were joined together over the shoulders (hence in Latin called superhumerale) by clasps or buckles of gold or precious stones, and fastened round the waist by a "curious girdle of gold, blue, purple, and fine twined linen" (Exodus 28:6-12).
The breastplate, with the Urim and Thummim, was attached to the ephod.