Merriam-Webster Collegiate Dictionary - hemorrhoid

 noun  Etymology: Middle English emeroides, plural, from Anglo-French emorroides, from Latin haemorrhoidae, from Greek haimorrhoides, from haimorrhoos flowing with blood, from haimo- hem- + rhein to flow — more at stream  Date: 14th century a mass of dilated veins in swollen tissue at the margin of the anus or nearby within the rectum — usually used in plural; called also piles