operose Synonyms

heavy laborious toilsome gruelling punishing hard backbreaking grueling arduous tough taxing strenuous sticky severe serious rugged rough thorny toilful labor-intensive labour-intensive time-consuming weighty trying not easy labor-consuming labour-consuming tricky problematic ambitious grinding grievous grave elaborate difficult difficile complicated complex hefty industrious intricate ponderous painful oppressive onerous nasty leaden knotty knotted involved