carcinoid n 1: a small tumor (benign or malignant) arising from the mucosa of the gastrointestinal tract; usually associated with excessive secretion of serotonin
carcinoid \carcinoid\ [From Gr. karki`nos, a crab + -oid.] n. A small tumor (benign or malignant) arising from the mucosa of the gastrointestinal tract; it is usually associated with excessive secretion of serotonin. [WordNet 1.5]