challenging

UK: /ˈtʃælɪndʒɪŋ/ US: /ˈtʃælɪndʒɪŋ/ ,(chal′in jing)

From the verb challenge: (⇒ conjugate)

challenging is: ⓘ

v pres p

WordReference Random House Learner's Dictionary of American English © 2026

chal•leng•ing /ˈtʃælɪndʒɪŋ/   adj. 

1. testing someone's skill or ability because of its difficulty:
   The exam was a challenging test.
2. questioning or demanding;
   defiant:
   His daughter gave him a challenging glare.

WordReference Random House Unabridged Dictionary of American English © 2026

chal•leng•ing  (chal′in jing), adj. 

1. offering a challenge;
   testing one's ability, endurance, etc:
   a challenging course; a challenging game.
2. stimulating, interesting, and thought-provoking:
   a challenging suggestion.
3. provocative;
   intriguing:
   a challenging smile.

• 1300–50; Middle English, as gerund, gerundive; 1835–45 for def. 1; see challenge, -ing²

chal′leng•ing•ly, adv. 

Collins Concise English Dictionary © HarperCollins Publishers::

challenging / ˈtʃælɪndʒɪŋ/ adjective

1. demanding or stimulating: a challenging new job

WordReference Random House Learner's Dictionary of American English © 2026

chal•lenge /ˈtʃælɪndʒ/   n., v., -lenged, -leng•ing. 
n. 

1. a call to compete in a contest or in a fight:
   [countable] I accept your challenge to a duel.
   [uncountable] A hint of challenge appeared on his face.
2. something that by its nature is a test or a difficult thing to accomplish:
   [countable] Space exploration offers a challenge to humankind.
   [uncountable] I'd like work with a bit more challenge than this useless drudgery.
3. a demand, request, or question to explain or justify something:
   [countable* ~ + to] His criticism was a challenge to every proposal we had made.

v. [~ + object]

4. to summon (someone) to a contest or fight:
   [~ + object + to + object] He challenged his foe to a duel.
5. to test (someone) because of its difficulty:
   This obstacle course will really challenge him.
6. to demand or question whether (something or someone) is correct, proper, or qualified:
   The leaders of the revolt challenged the dictator's authority.
7. Military to halt and demand identification from:
   The guard challenged the reporter when she tried to enter the army base.

chal•leng•er, n. [countable]

WordReference Random House Unabridged Dictionary of American English © 2026

chal•lenge  (chal′inj), n., v., -lenged, -leng•ing, adj. 
n. 

1. a call or summons to engage in any contest, as of skill, strength, etc.
2. something that by its nature or character serves as a call to battle, contest, special effort, etc.:
   Space exploration offers a challenge to humankind.
3. a call to fight, as a battle, a duel, etc.
4. a demand to explain, justify, etc.:
   a challenge to the treasurer to itemize expenditures.
5. difficulty in a job or undertaking that is stimulating to one engaged in it.
6. Military the demand of a sentry for identification or a countersign.
7. Law a formal objection to the qualifications of a particular juror, to his or her serving, or to the legality of an entire jury. Cf. peremptory challenge.
8. Government the assertion that a vote is invalid or that a voter is not legally qualified.
9. Physiology [Biol.] the process of inducing or assessing physiological or immunological activity by exposing an organism to a specific substance.
10. Sport [Hunting.] the crying of a hound on finding a scent.

v.t. 

11. to summon to a contest of skill, strength, etc.
12. to take exception to;
    call in question:
    to challenge the wisdom of a procedure.
13. to demand as something due or rightful.
14. Military to halt and demand identification or countersign from.
15. Law to take formal exception to (a juror or jury).
16. to have a claim to;
    invite;
    arouse;
    stimulate:
    a matter which challenges attention.
17. Government to assert that (a vote) is invalid.
18. Government to assert that (a voter) is not qualified to vote.
19. Physiology to expose an organism to a specific substance in order to assess its physiological or immunological activity.
20. [Archaic.] to lay claim to.

v.i. 

21. to make or issue a challenge.
22. Sport [Hunting.] (of hounds) to cry or give tongue on picking up the scent.

adj. 

23. donated or given by a private, corporate, or government benefactor on condition that the recipient raise an additional specified amount from the public:
    a challenge grant.

• Latin calumnia calumny
• Old French, variant of chalonge
• Middle English chalenge 1175–1225

chal′lenge•a•ble, adj. 
Synonyms

• 11. dare, bid, invite.
• 12. question, impute, doubt.

Collins Concise English Dictionary © HarperCollins Publishers::

challenge / ˈtʃælɪndʒ/ verb (mainly tr)

1. to invite or summon (someone to do something, esp to take part in a contest)
2. (also intr) to call (something) into question; dispute
3. to make demands on; stimulate: the job challenges his ingenuity
4. to order (a person) to halt and be identified or to give a password
5. to make formal objection to (a juror or jury)
6. to lay claim to (attention, etc)
7. to inject (an experimental animal immunized with a test substance) with disease microorganisms to test for immunity to the disease

noun

1. a call to engage in a fight, argument, or contest
2. a questioning of a statement or fact; a demand for justification or explanation
3. a demanding or stimulating situation, career, object, etc
4. a demand by a sentry, watchman, etc, for identification or a password
5. a formal objection to a person selected to serve on a jury (challenge to the polls) or to the whole body of jurors (challenge to the array)

Etymology: 13th Century: from Old French chalenge, from Latin calumnia calumny

ˈchallengeable adjective

ˈchallenger noun