oil

Pluraloils

Formsoils, oiling, oiled

1. 1
   liquid fatnouncountable or uncountable

   A thick, slippery liquid that does not mix with water, from plants, animals or minerals, especially the liquid fats used in cooking.

   The recipe calls for two tablespoons of oil and a pinch of salt.

   Heating the oil too quickly can make it smoke and turn bitter.

   UsageFor an amount, say some oil or a spoonful of oil; oils means kinds: cooking oils, nut oils.

2. 2
   petroleumnouncountable or uncountable

   Petroleum: the naturally occurring liquid pumped from deposits beneath the earth's surface.

   Geologists found oil trapped in porous rock far below the desert.

   The platform pumps crude oil from the seabed around the clock.

   UsageCommon in compounds: crude oil, an oil well, oil prices, an oil spill.

   Similarpetroleum, crude

   Note

   Crude in the ground rather than refined in the can: the sense behind phrases like the oil age, an oil strike, crude oil. The Economist in 2013 dates serious extraction to an 1859 oil strike in Pennsylvania, though the stuff had waterproofed boats in the Middle East some six thousand years ago. Source

   Checked 2 Nov 2026 · 3 facts

   • The Economist in 2013 dated extraction in earnest to an 1859 oil strike in Pennsylvania. en.wiktionary.org
   • Petroleum was used to waterproof boats in the Middle East some six thousand years ago. en.wiktionary.org
   • Crude oil is extracted from the ground and then refined into petroleum products. eia.gov
3. 3
   nouncountable or uncountable

   A liquid drawn from a plant and valued for its aroma or taste, or added to products for the skin, the hair, or health.

   A single drop of peppermint oil gives the frosting a cool, fresh flavor.

   The massage therapist blended eucalyptus and rosemary oils for my sore shoulders.

   UsageThe plant usually comes first: peppermint oil, tea tree oil. Oils means several kinds.

   Note

   Concentrated scents of this kind are called essential oils, the term used in aromatherapy and on product labels, and they are often blended into a milder carrier oil before going on the skin. Source

   Checked 2 Nov 2026 · 2 facts

   • Essential oils are concentrated aromatic substances obtained from plants. cancer.gov
   • Essential oils are often diluted in a carrier oil before application to the skin. cancercouncil.com.au
4. 4
   machine fluidnouncountable or uncountable

   A petroleum-based liquid used as a fuel or as a lubricant for machinery.

   The mechanic drained the dirty oil and poured in a fresh quart.

   Without enough oil, the bearings overheat and seize.

   UsageCommon in check the oil, change the oil and an oil change.

   Similarlubricant

5. 5
   verbtransitive

   To put oil on something, for example to make its parts move smoothly, to stop food sticking, or to protect or condition it.

   She oiled the sewing machine so the needle wouldn't stick.

   Mechanics oil the moving joints during every routine service.

   UsageOften in well-oiled: a well-oiled machine is something that runs smoothly.

   Similarlubricate, grease

   Note

   Machinery is the verb's home ground. E. J. Tyler and J. Quanjer's "The Steam Locomotive in Holland 1919-1954" (1955) has a driver standing between engine and platform "oiling the motion", the railwayman's phrase for the moving rods and joints. The past participle reaches beyond machines, though: Margery Allingham's The China Governess (1962) gives a character oiled black curls, oil dressing hair rather than easing parts. Source

   Checked 31 Oct 2026 · 6 facts

   • E. J. Tyler and J. Quanjer wrote “The Steam Locomotive in Holland 1919-1954”, published in 1955. en.wiktionary.org
   • The article describes a driver standing between his engine and the platform while “oiling the motion”. en.wiktionary.org
   • In locomotive terminology, “motion” denotes the moving rods and associated mechanism. en.wikipedia.org
   • Margery Allingham wrote The China Governess. en.wikipedia.org
   • The novel was first published in 1962; 1963 is the British edition's date. diogenes.ch
   • The novel describes a character with “oiled black curls”, referring to oil applied to hair. en.wiktionary.org
6. 6
   paintingnouncountable

   A painting made with oil paints.

   A small oil of a country church hung above the mantel.

   The museum displayed early oils by the Dutch masters.

   UsageA painter works in oil but hangs an oil; often plural with a name: Picasso's oils.

   Note

   John Ulric Nef, in 1973, could not put Picasso's oils in the same class as Cezanne's. Source

   Checked 2 Nov 2026 · 2 facts

   • The cited writing by John Ulric Nef appeared in 1973. openlibrary.org
   • Nef wrote that he could not put Picasso's oil paintings in the same class as Cezanne's. en.wiktionary.org
7. 7
   artist's paintnouncountable or uncountable

   Paint made by mixing pigment with a drying oil, valued by artists for its rich color and slow drying.

   She thinned the oil with a little turpentine before laying in the sky.

   Working in oil lets a painter rework the same passage for days.

   UsageWith no article: paint in oil, work in oil, like in watercolor.

   Note

   A painter's material whose behavior comes from its binder: pigment held in a drying oil such as linseed. That oil hardens by oxidation, not by evaporation, so the paint stays workable long enough to blend on the canvas and cures to a durable, luminous film. Source

   Checked 2 Nov 2026 · 7 facts

   • The binder determines characteristic properties of the paint. npg.org.uk
   • Oil paint contains pigment dispersed in a drying oil, such as linseed oil. en.wikipedia.org
   • The oil hardens through oxidation and chemical cross-linking. pmc.ncbi.nlm.nih.gov
   • Evaporation is not the mechanism by which the oil binder hardens. canada.ca
   • Slow drying permits artists to blend paint after applying it. mauritshuis.nl
   • Dried oil paint forms a durable film. canada.ca
   • Oil painting can produce a luminous surface. npg.org.uk

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