The Collaborative International Dictionary of English v.0.48:

ill-use \ill-use\ v.
   1. to treat badly.

   Syn: mistreat, maltreat, abuse, ill-treat.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

ill-use
    v 1: treat badly; "This boss abuses his workers"; "She is always
         stepping on others to get ahead" [syn: mistreat,
         maltreat, abuse, ill-use, step, ill-treat]

Moby Thesaurus II by Grady Ward, 1.0:

63 Moby Thesaurus words for "ill-use":
   abuse, active use, appliance, application, atrocity, batter, bleed,
   bleed white, bruise, buffet, consumption, do violence to,
   do wrong by, do wrong to, drain, employ, employment, exercise,
   exertion, exploit, good use, hard usage, hard use, ill use,
   ill-treat, ill-treatment, ill-usage, impose upon, injure, injury,
   knock about, make use of, maltreat, maltreatment, manhandle,
   manipulate, maul, milk, mishandle, mistreat, mistreatment, misuse,
   molest, molestation, outrage, play on, presume upon, rough,
   rough up, rough usage, savage, stroke, suck dry, take advantage of,
   usage, use, use ill, using up, violation, violence, work on,
   work upon, wrong use