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

Putting the cotton balls in glass jars with open lids helps the scent dissipate more slowly for longer effectiveness, and they can be easily refreshed by adding more drops of essential oils to the jar. — The Spruce, 4 Aug. 2026

The Mosquito Repellent Wristbands feature natural essential oils. — ABC News, 3 Aug. 2026

Other natural pesticides — like insecticidal soaps or essential oils (rosemary, thyme, peppermint) — may also cause allergic reactions in humans and are unsafe to swallow, says Runyon. — Nicole Hernandez, USA Today, 1 Aug. 2026

Plus, it’s infused with a blend of over 30 essential oils and nutrients, which nourish the scalp, add shine, and, of course, promote growth. — Isabel Bekele, InStyle, 26 July 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