n. 25B6; noun
he accepted the challenge : DARE, provocation; summons.
a challenge to his leadership : TEST, questioning, dispute, stand, opposition, confrontation.
it was proving quite a challenge : PROBLEM, difficult task, test, trial.
25B6; verb
we challenged their statistics : QUESTION, disagree with, dispute, take issue with, protest against, call into question, object to.
he challenged one of my men to a duel : DARE, summon, throw down the gauntlet to.
changes that would challenge them : TEST, tax, strain, make demands on; stretch, stimulate, inspire, excite.