What does sebum mean?
Sebum is the natural oil produced by the sebaceous glands in the skin. It lubricates the skin and hair, helps form a protective barrier against moisture loss and external substances, and can contribute to the appearance of oily or shiny skin. In medical and cosmetic contexts, the word is used to discuss conditions involving excessive or insufficient sebum, clogged pores, acne, and related skin problems. Although “skin oil” can describe the substance in general speech, sebum is the more precise scientific term. The word derives from Latin, where sebum referred to tallow or grease, an association that reflects sebum’s oily character. Sebum is normally treated as an uncountable mass noun, particularly when describing a substance or its production rather than individual portions of it.
nounSebum is the oily substance secreted by the sebaceous glands of the skin. It helps lubricate and protect the skin and hair.
- An oily secretion produced by the sebaceous glands of the skin, which lubricates and protects the skin and hair.
"Excess sebum can contribute to oily skin and clogged pores."
"The dermatologist recommended a gentle cleanser for skin that produces too much sebum."
"The animal's coat was coated with a layer of sebum that gave it a glossy appearance."
Rarely used; sebum is normally uncountable, especially when referring to the substance or its production.
"The analysis identified different sebums produced by the skin samples."
Sebum comes from the Latin word for tallow: the everyday name for skin oil preserves the idea of grease.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does sebum come from?
Sebum comes from Latin sebum, meaning tallow, grease, or oily fat. The English word entered medical and biological usage for the oily secretion of the skin’s sebaceous glands. Related terms include sebaceous, referring to the glands that produce sebum, and seborrheic, associated with an excessive or abnormal accumulation of sebum.
Related word forms
How sebum is actually used
Usually used in technical, medical, dermatological, or scientific contexts. It is an uncountable noun in ordinary usage, although the plural 'sebums' occurs occasionally in technical writing.
Easily confused with sebum
Sebum is an oily skin secretion, whereas serum is a watery or protein-rich fluid found in blood and other bodily fluids.