Synonyms and related words :
boresome, boring, burdensome, draining, exhausting, fatiguesome, fatiguing, grinding, grueling, harsh, heavy, irksome, killing, onerous, oppressive, overburdensome, punishing, straining, stressful, stupefyingly boring, stuporific, tiresome, tiring, toilsome, trying, tyrannous, weariful, wearing, wearisome, weighty, yawny