deputise

from WordNet (r) 3.0 (2006)

deputise
    v 1: act as a substitute; "She stood in for the soprano who
         suffered from a cold" [syn: {substitute}, {deputize},
         {deputise}, {step in}]
    2: appoint as a substitute [syn: {depute}, {deputize},
       {deputise}]

from The Collaborative International Dictionary of English v.0.48

deputise \dep"u*tise\ (d[e^]p"[-u]*t[imac]z), v. t.
   same as {deputize}.

   Syn: depute, deputize.
        [WordNet 1.5]