1. Pertaining to, of the nature of, or resembling tallow or fat; oily, greasy: The French fries were so sebaceous that Susan had to use a napkin to wipe her fingers each time she ate one!
2. Containing, or pertaining to, sebum, the oily secretion of a cutaneous gland: The sebaceous glands in men are larger than in women, and therefore perhaps explains why men have more problems with dandruff that women.

A holocrine gland in the skin that secretes sebum into hair follicles: Judy learned about the sebaceous gland and that it was important for the growth of hair on a person's body.