\Ar"du*ous\ (?; 135), a. [L. arduus steep, high; akin to
Ir. ard high, height.]
1. Steep and lofty, in a literal sense; hard to climb.
         Those arduous paths they trod.        --Pope.
2. Attended with great labor, like the ascending of
   acclivities; difficult; laborious; as, an arduous
   employment, task, or enterprise.
Syn: Difficult; trying; laborious; painful; exhausting.
Usage: {Arduous}, {Hard}, {Difficult}. Hard is simpler,
       blunter, and more general in sense than difficult; as,
       a hard duty to perform, hard work, a hard task, one
       which requires much bodily effort and perseverance to
       do. Difficult commonly implies more skill and sagacity
       than hard, as when there is disproportion between the
       means and the end. A work may be hard but not
       difficult. We call a thing arduous when it requires
       strenuous and persevering exertion, like that of one
       who is climbing a precipice; as, an arduous task, an
       arduous duty. ``It is often difficult to control our
       feelings; it is still harder to subdue our will; but
       it is an arduous undertaking to control the unruly and
       contending will of others.''