This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

adj. Calling for full use of one's abilities or resources in a difficult but stimulating effort: a challenging course of study; a challenging role for an inexperienced performer.

adj. Absorbing; intriguing: a challenging idea.

v. Present participle of challenge.

adj. Difficult, hard to do.

adj. requiring full use of one's abilities or resources.

adj. disposed to or engaged in defiance of established authority.

adj. stimulating interest or thought

adj. disturbingly provocative

adj. requiring full use of your abilities or resources

"It was perhaps an understatement, but the evaluation continued, “The word challenging appears to personify this individual, who may well view life in terms of overcoming obstacles and challenges, even if he has to create them artificially . . .”"

stimulating    provocative    difficult    hard   

unchallenging   

challenge   

ambitious    demanding    insubordinate    resistant    resistive   

challenge