Sebaceous adj. (Physiol.) Pertaining to, or secreting, fat; composed of fat; having the appearance of fat; as, the sebaceous secretions of some plants, or the sebaceous humor of animals. Sebaceous cyst (Med.), a cyst formed by distention of a sebaceous gland, due to obstruction of its excretory duct.
Sebaceous glands (Anat.), small subcutaneous glands, usually connected with hair follicles. They secrete an oily semifluid matter, composed in great part of fat, which softens and lubricates the hair and skin.