WordNet: effortful

requiring great physical effort

• also see difficult, hard

• similar to arduous, backbreaking, grueling, gruelling, hard, heavy, laborious, operose, punishing, toilsome

• similar to dragging

• similar to exhausting, tiring, wearing, wearying

• similar to heavy, labored, laboured

• similar to labor-intensive, labour-intensive

• similar to leaden, plodding

• similar to Sisyphean

• similar to arduous, straining, strenuous

effortful

• (englanti) effortless (antonym)

• (englanti) effortfulness (derivationally related)
• (suomi) vaativa (synonyymi)