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Synonyms

oily

American  
[oi-lee] / ˈɔɪ li /

adjective

oilier, oiliest

  1. smeared or covered with oil; greasy.

    an oily road surface.

  2. of the nature of, consisting of, or resembling oil.

  3. of or relating to oil.

  4. full of or containing oil.

  5. smooth or unctuous, as in manner or speech.

    an oily hypocrite.
    Synonyms:
    smarmy

adverb

  1. in an oily manner.

oily British  
/ ˈɔɪlɪ /

adjective

  1. soaked in or smeared with oil or grease

  2. consisting of, containing, or resembling oil

  3. flatteringly servile or obsequious

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • nonoily adjective
  • oilily adverb
  • oiliness noun
  • unoily adjective

Etymology

Origin of oily

First recorded in 1520–30; oil + -y 1

Explanation

Oily things are greasy, slippery, or covered with oil — think a bowl of oily pasta or the oily garage floor after you've been tinkering with your motorcycle's engine. Anything containing oil, covered in oil, or resembling oil is oily. A batch of muffins might taste weirdly oily when you use too much butter, and the rags lying around a car repair shop are mostly black and oily. Your brother's hair will probably be pretty oily after he refuses to wash it for a month. Since the sixteenth century, oily has also had the figurative meaning of "insincerely flattering or slick," like an oily car salesman.

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

"It's getting worse every day. Green, black, oily," Rodríguez complains.

From BBC • Jan. 29, 2026

These targets can be achieved by eating more oily fish, such as salmon or mackerel, or through supplementation where needed.

From Science Daily • Dec. 9, 2025

After nearly eight months of "oily and salty" prison food, Barbie told the Sunday Times she would like to have some salad and marmite, while Peter was hankering for baked beans.

From BBC • Sep. 22, 2025

I’m team salsa macha — toasty, oily and laced with peanuts and chiles.

From Salon • Aug. 5, 2025

His pale, oily face gleamed and bobbed in front of her eyes.

From "Atonement" by Ian McEwan

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.