disturbingly provocative; "an intriguing smile"

requiring full use of one's abilities or resources; as, challenging task.

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

disposed to or engaged in defiance of established authority.

when a player challenges their opponent. The most direct way to challenge is to tackle, however it is not always the best. Intercepting a pass is the best way of challenging but leaves the defender in a bad position to recover if they are not successful. See also Challenge.

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

interesting; difficult.