boring (part of speech: verb)
difficulty (part of speech: noun)
formidability, ordeal, tightness, strenuousness, trickiness, difficulty, complication, onerousness, ticklishness, adversity, toughness, hardness, oppressiveness, fussiness, cantankerousness, roughness, contrariness, stressfulness, knottiness, cumbersomeness, harshness, wearisomeness, complexity, arduousness, severity
difficult (part of speech: adjective)
formidable, stressful, cumbersome, contrary, severe, arduous, knotty, demanding, harsh, oppressive, trying, thorny, tough, finicky, hard, fussy, tricky, difficult, uphill, toilsome, strenuous, wearisome, complicated, complex, cantankerous, ticklish, rugged, burdensome, wearing, grinding, adverse, tight, laborious, rough, onerous, troublesome, bothersome
- Only the strongest can stand it, a wearying, back- breaking task. - "Cuba, Old and New", Albert Gardner Robinson.
- Between then and now lies the night, stretching like a bar of verdure across wearying sands. - "The Mettle of the Pasture", James Lane Allen.
- This was excellent practice for the troops, as it taught them the, necessity of keeping a good look- out; at the same time it was very wearying, as the men had to work hard all day, and they were kept awake at night. - "Ismailia", Samuel W. Baker.