The Collaborative International Dictionary of English v.0.48:

Impose \Im*pose"\, v. i.
   To practice tricks or deception.
   [1913 Webster]

   To impose on or To impose upon,
   (a) to pass or put a trick on; to delude; to cheat; to
       defraud. "He imposes on himself, and mistakes words for
       things." --Locke.
   (b) to place an unwelcome burden or obligation on (another
       person); as, she imposed on her friend to drive her
       daughter to school.
   (c) to take unfair advantage of (a person, a friendship); as,
       he imposed on his friendship with The Mayor to gain
       business.
       [1913 Webster +PJC]

The Collaborative International Dictionary of English v.0.48:

Impose \Im*pose"\, v. t. [imp. & p. p. Imposed; p. pr. & vb.
   n. Imposing.] [F. imposer; pref. im- in + poser to place.
   See Pose, v. t.]
   1. To lay on; to set or place; to put; to deposit.
      [1913 Webster]

            Cakes of salt and barley [she] did impose
            Within a wicker basket.               --Chapman.
      [1913 Webster]

   2. To lay as a charge, burden, tax, duty, obligation,
      command, penalty, etc.; to enjoin; to levy; to inflict;
      as, to impose a toll or tribute.
      [1913 Webster]

            What fates impose, that men must needs abide.
                                                  --Shak.
      [1913 Webster]

            Death is the penalty imposed.         --Milton.
      [1913 Webster]

            Thou on the deep imposest nobler laws. --Waller.
      [1913 Webster]

   3. (Eccl.) To lay on, as the hands, in the religious rites of
      confirmation and ordination.
      [1913 Webster]

   4. (Print.) To arrange in proper order on a table of stone or
      metal and lock up in a chase for printing; -- said of
      columns or pages of type, forms, etc.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Impose \Im*pose"\, n.
   A command; injunction. [Obs.] --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

impose
    v 1: compel to behave in a certain way; "Social relations impose
         courtesy" [syn: enforce, impose]
    2: impose something unpleasant; "The principal visited his rage
       on the students" [syn: inflict, bring down, visit,
       impose]
    3: impose and collect; "levy a fine" [syn: levy, impose]

Moby Thesaurus II by Grady Ward, 1.0:

154 Moby Thesaurus words for "impose":
   abuse, administer the Eucharist, anoint, appoint, ask, ask for,
   assess, authorize, barge in, blackmail, break in, break in upon,
   brook no denial, burden, burden with, burst in, butt in, call for,
   challenge, charge, charge for, charge in, chrism, claim,
   clamor for, come between, command, compel, compose, confirm,
   constrain, crash, crash in, crash the gates, creep in, crowd in,
   cry for, cut in, decree, demand, dictate, do duty, drag in,
   edge in, elbow in, encroach, enjoin, entrench, exact, exploit,
   extort, fasten upon, fob, foist, foist in, force, freight with,
   horn in, impinge, impose on, impose upon, indent, infiltrate,
   inflict, inflict on, inflict upon, infringe, insinuate, interfere,
   interlope, interpose, interrupt, intervene, intrude, invade,
   irrupt, issue an ultimatum, justify, lade, lay, lay down,
   lay hands on, lay on, leave no option, levy, make a demand,
   make dutiable, make free, make obligatory, make up, minister,
   misuse, necessitate, oblige, obtrude, officiate, ordain, order,
   order up, overrun, perform a rite, perform service, pi, pi a form,
   place, place an order, prescribe, press in, presume, pro rata,
   prorate, push in, put, put down, put in requisition, put on,
   put upon, require, requisition, rush in, saddle, saddle with,
   screw, set, set in print, slink in, slip in, smash in, sneak in,
   squeeze in, steal in, stick for, storm in, subject to,
   take advantage of, take liberties, take no denial, task, tax,
   throng in, thrust in, tithe, trench, trespass, use, visit, warn,
   weight down with, wish, work in, worm in, wreak, wreck,
   yoke with