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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.

If Step 3’s pretextual jury-striking analysis can be skipped in practice and insulated on review, Batson’s promise becomes thinner still.

From Slate • Apr. 10, 2026

Persistent weakness in the currency can negatively impact everything, feeding into higher prices for consumers, lower corporate margins, bigger government deficits and thinner capital flows into the stock market.

From BBC • Apr. 6, 2026

“More people are struggling to pay for care and basic needs than ever before and the safety net’s being stretched thinner and thinner,” Balch said.

From The Wall Street Journal • Mar. 3, 2026

When heating intensifies, the ice shell can melt and become thinner.

From Science Daily • Mar. 2, 2026

As for Jason, he looked thinner, taller, and more careworn.

From "The House of Hades" by Rick Riordan

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.