verb (used with object), de·terred, de·ter·ring.

to discourage or restrain from acting or proceeding: The large dog deterred trespassers.
to prevent; check; arrest: timber treated with creosote to deter rot.

Origin of deter

1570–80; < Latin dēterrēre to prevent, hinder, equivalent to dē- de- + terrēre to frighten
Related formsde·ter·ment, nounde·ter·ra·ble, adjectivede·ter·ra·bil·i·ty, nounde·ter·rer, nounun·de·ter·ra·bil·i·ty, nounun·de·ter·ra·ble, adjectiveun·de·ter·ra·bly, adverbun·de·terred, adjectiveun·de·ter·ring, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for undeterred

Contemporary Examples of undeterred

Historical Examples of undeterred

  • But she continued, undeterred: "You are a coward—a pitiful coward," she told him.

    Mistress Wilding

    Rafael Sabatini

  • Undeterred by his failure, de Spain held his ground as long as he dared.

    Nan of Music Mountain

    Frank H. Spearman

  • But the chief priests and scribes and elders of the people were undeterred.

    Jesus the Christ

    James Edward Talmage

  • Undeterred by any sense of delicacy, Quin pushed open the door and bolted in.


    Alice Hegan Rice

  • Undeterred by this, the Moana let go and followed with the same result.

    A Son Of The Sun

    Jack London

British Dictionary definitions for undeterred



not discouraged or dissuaded


verb -ters, -terring or -terred

(tr) to discourage (from acting) or prevent (from occurring), usually by instilling fear, doubt, or anxiety
Derived Formsdeterment, noun

Word Origin for deter

C16: from Latin dēterrēre, from de- + terrēre to frighten
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

Word Origin and History for undeterred

c.1600, from un- (1) "not" + past participle of deter.



1570s, from Latin deterrere "to frighten from, discourage from," from de- "away" (see de-) + terrere "frighten" (see terrible). Deterrent is from 1829.

Online Etymology Dictionary, © 2010 Douglas Harper