Challenging (adjective / verb (present participle)) — صعب بطريقة تختبر القدرة وتدعو للنمو: Difficult in a way that tests ability and invites growth — demanding, stimulating, not easy; also the present participle of challenge; a positive stretch when calibrated well Below are 8 words with a similar meaning; the linked ones have full GL Dictionary entries with their meaning in Arabic.
difficulttestingstimulatingexactingtoughstretching
Having a strong desire for success or achievement; requiring great effort; demanding
Given to arguing or debate — ready to challenge claims, dispute points, or push back with reasons (variant spelling of 'argumentative')
showing open resistance or bold disobedience; characterized by a refusal to obey authority or conform to established norms, often in a bold or aggressive manner
Causing anger or strong reaction, often deliberately; also thought-provoking.