Dictionary.com
Thesaurus.com
Synonyms

zealous

American  
[zel-uhs] / ˈzɛl əs /

adjective

  1. full of, characterized by, or due to zeal; ardently active, devoted, or diligent.

    Synonyms:
    warm, passionate, intense, fervent, fervid, eager, enthusiastic
    Antonyms:
    lackadaisical, apathetic
zealous British  
/ ˈzɛləs /

adjective

  1. filled with or inspired by intense enthusiasm or zeal; ardent; fervent

"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

  • nonzealous adjective
  • nonzealously adverb
  • nonzealousness noun
  • underzealous adjective
  • underzealously adverb
  • underzealousness noun
  • unzealous adjective
  • unzealously adverb
  • zealously adverb
  • zealousness noun

Etymology

Origin of zealous

First recorded in 1520–30; from Medieval Latin zēlōsus; zeal, -ous

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.

The dolls became so hard to come by that some were resold for as much as 20 times their retail prices, while zealous fans traveled to China to hunt down fast-selling goods.

From The Wall Street Journal • Jan. 31, 2026

Unwittingly, zealous regulators have turned stock markets into the casinos that commissioner Crenshaw deplores.

From Barron's • Jan. 2, 2026

In Dumbarton the situation was stoked by zealous local ministers, with the Covenanter movement having considerable influence at the time.

From BBC • Oct. 30, 2025

And yet he was so not zealous about this perfect past.

From Slate • May 9, 2025

Their leader was a zealous, loud-voiced girl with short hair and large eyes.

From "Red Scarf Girl: A Memoir of the Cultural Revolution" by Ji-li Jiang

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.