The Collaborative International Dictionary of English v.0.48:

hostile takeover \hostile takeover\ n. (Finance)
   the purchase of a controlling interest in a publicly-traded
   company against the wishes of the current management.

   Note: A person who is the main principal in performing such a
         buyout is called a corporate raider.

   Syn: hostile buyout.
        [PJC]

The Collaborative International Dictionary of English v.0.48:

takeover \take"o*ver\ n. (Business, Finance)
   The acquisition of ownership of one company by another
   company, usually by purchasing a controlling percentage of
   its stock or by exchanging stock of the purchasing company
   for that of the purchased company. It is a hostile takeover
   if the management of the company being taken over is opposed
   to the deal. A hostile takeover is sometimes organized by a
   corporate raider.

   Syn: acquisition, buyout
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

hostile takeover
    n 1: a takeover that is resisted by the management of the target
         company