[ˈtʃalɪn(d)ʒ], (Noun)

Definitions:
- a call to someone to participate in a competitive situation or fight to decide who is superior in terms of ability or strength
(e.g: he accepted the challenge)

- a call to prove or justify something
(e.g: a challenge to the legality of the banning order)

- the administration of an immunogenic or infectious agent to an animal or person, in order to study the resulting immune response or measure the efficacy of a vaccine
(e.g: challenge trials have yielded positive results when carefully and ethically conducted)


Phrases:

Origin:
Middle English (in the senses ‘accusation’ and ‘accuse’): from Old French chalenge (noun), chalenger (verb), from Latin calumnia ‘calumny’, calumniari ‘calumniate’

[ˈtʃalɪn(d)ʒ], (Verb)

Definitions:
- invite (someone) to engage in a contest
(e.g: he challenged one of my men to a duel)

- dispute the truth or validity of
(e.g: it is possible to challenge the report's assumptions)

- administer an immunogenic or infectious agent to an animal or person, in order to study the resulting immune response or measure the efficacy of a vaccine
(e.g: the mice were challenged with the influenza virus)


Phrases:

Origin:
Middle English (in the senses ‘accusation’ and ‘accuse’): from Old French chalenge (noun), chalenger (verb), from Latin calumnia ‘calumny’, calumniari ‘calumniate’