Se‐ba″ceous (?), a. [NL. sebaceus, from L. sebum tallow, grease.] (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.