Synonyms for challenging

Verb

1. challenge, dispute, gainsay, contest, contend, repugn

usage: take exception to; "She challenged his claims"

2. challenge, invite, bid

usage: issue a challenge to; "Fischer challenged Spassky to a match"

3. challenge, request, bespeak, call for, quest

usage: ask for identification; "The illegal immigrant was challenged by the border guard"

4. challenge, take exception, object

usage: raise a formal objection in a court of law

Adjective

1. ambitious, challenging, difficult (vs. easy), hard

usage: requiring full use of your abilities or resources; "ambitious schedule"; "performed the most challenging task without a mistake"

2. challenging, thought-provoking, stimulating (vs. unstimulating)

usage: stimulating interest or thought; "a challenging hypothesis"; "a thought-provoking book"

3. challenging, intriguing, provocative (vs. unprovocative)

usage: disturbingly provocative; "an intriguing smile"