essential oil

noun

: any of a class of volatile oils that give plants their characteristic odors and are used especially in perfumes and flavorings, and for aromatherapy compare fixed oil

Examples of essential oil in a Sentence

Recent Examples on the Web

Alternatively, Koala Eco mild dishwashing liquid with essential oils, also diluted with water, works as a natural polish for your wood furniture. —Sunshine Flint, Architectural Digest, 2 Apr. 2026

Even nontoxic scents, derived from essential oils, can cause skin reactions in very sensitive users, so opt for a fragrance-free deodorant if that applies to you. —Bestreviews, Chicago Tribune, 31 Mar. 2026

It’s made with over 20 essential oils to help fuel hair growth, including rosemary and castor oils. —Kansas City Star, 27 Mar. 2026

Rather than leaving oil in your hair throughout the day, applying it generously before shampooing allows the essential oils to sit on the scalp and penetrate the hair without leaving you looking greasy. —Miami Herald, 26 Mar. 2026

Word History

First Known Use

1674, in the meaning defined above

Rhymes for essential oil

• aerofoil
• cinquefoil
• hydrofoil
• quatrefoil
• airfoil
• benzoyl
• despoil
• embroil
• etoile
• gargoyle
• recoil
• subsoil

Medical Definition

essential oil

noun

: any of a large class of volatile odoriferous oils of vegetable origin that give plants their characteristic odors and often other properties, that are obtained from various parts of the plants (as flowers, leaves, or bark) by steam distillation, expression, or extraction, that are usually mixtures of compounds (as aldehydes or esters), and that are used often in the form of essences in perfumes, flavorings, and pharmaceutical preparations

called also ethereal oil, volatile oil

compare fatty oil, fixed oil