lijkt op: arduous, backbreaking, grueling, gruelling, hard, heavy, laborious, operose, punishing, toilsome | dragging | exhausting, tiring, wearing, wearying | heavy, labored, laboured | labor-intensive, labour-intensive | leaden, plodding | Sisyphean | arduous, straining, strenuous.

zie ook: difficult, hard.

is het tegengestelde van: effortless.

afleiding: effortfulness.