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Synonyms

thinner

1 American  
[thin-er] / ˈθɪn ər /

noun

  1. a volatile liquid, as turpentine, used to dilute paint, varnish, rubber cement, etc., to the desired or proper consistency.

  2. a person who adds thinners to paints, varnishes, etc.

  3. a person who specializes in weeding plants, pruning shrubbery, thinning fruit, etc.

thinner 2 American  
[thin-er] / ˈθɪn ər /

adjective

  1. comparative of thin.

thinner British  
/ ˈθɪnə /

noun

  1. (often plural, functioning as singular) a solvent, such as turpentine, added to paint or varnish to dilute it, reduce its opacity or viscosity, or increase its penetration into the ground

"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

Etymology

Origin of thinner

First recorded in 1825–35; thin + -er 1

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.

Thinner ice leads to fewer grounded ridges with deep enough bases to anchor the ice to the seafloor.

From Science Daily • Mar. 27, 2026

Thinner market conditions could add downward pressure on prices.

From Barron's • Feb. 17, 2026

“She was super to work with and very talented,” said Dr. Carl Lavie, who collaborated with her on his 2014 book “The Obesity Paradox: When Thinner Means Sicker and Heavier Means Healthier.”

From Los Angeles Times • Dec. 8, 2023

Thinner skins and a lack of seeds are supposed to reduce bitterness, which is where the name “burpless” came from, since they are supposed to be easier to digest.

From Seattle Times • Jun. 11, 2022

Thinner a good deal since her marriage, she seemed to him to have grown taller, to have gained in dignity and presence, as she stood there before him, her angry eyes fixed upon his face.

From A Lost Leader by Oppenheim, E. Phillips (Edward Phillips)

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.