challenging Definition

difficult, hard, ambitious, intriguing, stimulating, provocative, thought-provoking, tough, daunting, tricky, rewarding, stressful, arduous, perilous, problematic, complicated, exciting, interesting, demanding, problematical, troublesome, onerous, strenuous, contentious, inspiring, formidable, complex, invigorating, motivating, exhilarating, harsh, thorny, rigorous, aggressive, uphill, critical, rough, encouraging, contesting, difficulty, painful, dire, burdensome, intense, disadvantageous, daring, intractable, refreshing, pressing, thrilling, grim, cumbersome, defying, stringent, awkward, easy, laborious, exacting, adventurous, knotty, herculean, inspirational, serious, troubled, bold, energizing, elusive, severe, hardship, defiant, delicate, promising, intensive, adverse, audacious, intricate, threatening, vibrant, requiring, fearsome, sensitive, rugged, undermining, sophisticated, questioning, objecting, nurturing, trying, uneasy, disputing, against, picky, fostering, finicky, painstaking, stimulative, refuting, spurring, defiance, abnormal,