قمحدالقَمَحْدُوَةُ What is behind the head; (S, in art. قحد; and Msb;) that is to say, (Msb,) the [occiput or] hinder part of the back of the head; (T, Msb, K;) i. e., the surface between the ذُؤَابَة [here app. meaning the hair that surrounds the round part of the head] and what is termed فَأْسُ القَفَا [or the small protuberance above the back of the neck]: (T:) also, the protuberance above the back of the neck, (L, K,) between the ذُؤَابَة [see above] and the back of the neck, sloping down from the هَامَة [or middle, or crown, or top, of the head]; it is the part of the head which touches the ground when a man lies on his back: (L:) also, the upper part of the back of the head: (L, K:) or that part of the bone of the head which projects over the back of the neck; the هامة being above it; and the قَذَال, below it, next the part of the back of the neck that is between the ears: (Az, L:) pl. قَمَاحِدُ (S, L, K, &c.) and قَمَاحِيدُ and قَمَحْدُوَاتٌ. (L.) Accord. to J and AHei, the م is an augmentative letter; but others hold it to be a radical; and F says, that J's mentioning this word in art. قحد requires consideration. (TA.)