Dictionary.com
Thesaurus.com
Synonyms

defection

American  
[dih-fek-shuhn] / dɪˈfɛk ʃən /

noun

  1. desertion from allegiance, loyalty, duty, or the like; apostasy.

    His defection to East Germany was regarded as treasonable.

    Antonyms:
    loyalty
  2. failure; lack; loss.

    He was overcome by a sudden defection of courage.


defection British  
/ dɪˈfɛkʃən /

noun

  1. the act or an instance of defecting

  2. abandonment of duty, allegiance, principles, etc; backsliding

  3. another word for defect defect

"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

Etymology

Origin of defection

1535–45; < Latin dēfectiōn- (stem of dēfectiō ), equivalent to dēfect ( us ) ( see defect) + -iōn- -ion

Explanation

Is your team so bad you have begun supporting a rival team? Then you're guilty of defection — the act of shifting your support to a new cause. Most people won't thank you for your defection. No matter how much you might believe in the new sports team, or political party, or whatever, defection is generally used as a critical term. Defection implies a lack of character — as you can tell by looking at its Latin roots, which come from the word defectionum, meaning "desertion, revolt, failure." Clearly, no one likes a defector.

Keep Reading on Vocabulary.com

Vocabulary lists containing defection

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.

See Examples For:

In just six months, he has helped orchestrate the defection of five lawmakers—representing both the right and left of the political spectrum, from different parts of Canada—to his governing Liberal caucus.

From The Wall Street Journal Apr. 14, 2026

That’s what the defection of his largest influencers portends.

From Salon Apr. 10, 2026

Customer defection is of increasing concern for both airline management and shareholders, according to ASCI.

From MarketWatch Apr. 6, 2026

Whitford's defection came a day after he voted with his Reform UK colleagues to pass the party's first county council budget after it took control of the authority after May's local elections.

From BBC Feb. 20, 2026

“You know, Comrade Singh, there is one thing I learned during my defection: Everybody loves a happy assimilation story.”

From "Beauty Queens" by Libba Bray

Vocabulary.com logo
by dictionary.com

Dictionary.com's Learning Companion

Go beyond just looking up words.
Remember them forever with VocabTrainer.

Start training