<p><strong>Adjective:</strong></p><ul><li>Characterized by or involving toil; laborious or fatiguing.</li><li>Synonyms: strenuous, arduous, wearisome.</li><li>Requiring or using much energy and vigor; strenuous: making an arduous effort.</li><li>Hard to climb; steep: an arduous path up the hill.</li><li>Hard to endure; full of hardships; severe: an arduous winter.</li></ul><p><strong>End of Response</strong></p>