The Collaborative International Dictionary of English v.0.48:

Investment \In*vest"ment\, n.
   1. The act of investing, or the state of being invested.
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   2. That with which anyone is invested; a vestment.
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            Whose white investments figure innocence. --Shak.
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   3. (Mil.) The act of surrounding, blocking up, or besieging
      by an armed force, or the state of being so surrounded.
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            The capitulation was signed by the commander of the
            fort within six days after its investments.
                                                  --Marshall.
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   4. The laying out of money in the purchase of some species of
      property; also, the amount of money invested, or that in
      which money is invested.
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            Before the investment could be made, a change of the
            market might render it ineligible.    --A. Hamilton.
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            An investment in ink, paper, and steel pens.
                                                  --Hawthorne.
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WordNet (r) 3.0 (2006):

investment
    n 1: the act of investing; laying out money or capital in an
         enterprise with the expectation of profit [syn:
         investing, investment]
    2: money that is invested with an expectation of profit [syn:
       investment, investment funds]
    3: the commitment of something other than money (time, energy,
       or effort) to a project with the expectation of some
       worthwhile result; "this job calls for the investment of some
       hard thinking"; "he made an emotional investment in the work"
    4: outer layer or covering of an organ or part or organism
    5: the act of putting on robes or vestments
    6: the ceremonial act of clothing someone in the insignia of an
       office; the formal promotion of a person to an office or rank
       [syn: investment, investiture]

Moby Thesaurus II by Grady Ward, 1.0:

111 Moby Thesaurus words for "investment":
   accouterment, aerial tactics, airborne tactics, appanage, apparel,
   applied tactics, armament, armored tactics, array, attire,
   barrier tactics, bedizenment, beleaguerment, besiegement, blockade,
   blockading, catering, cavalry tactics, chandlery, clothes,
   clothing, costume, defensive strategy, diversion, dot, dower,
   dowry, drapery, dress, dressing, duds, empowerment, enablement,
   encirclement, encompassment, endowment, envelopment, equipment,
   fashion, fatigues, feathers, feint, fig, finding, fire tactics,
   fitting out, foundation, furnishing, furnishment, garb, garments,
   gear, guise, habiliment, habit, infantry tactics, infiltration,
   investiture, jointure, legal jointure, linen, logistics,
   marriage portion, mob tactics, mobile tactics, outfitting,
   pincer movement, pincers movement, plunge, portion, preparation,
   prime investment, procurement, providing, provision, provisioning,
   purveyance, rags, raiment, reinforcement, replenishment, resupply,
   retailing, risk, robes, selling, settlement, shock tactics, siege,
   speculation, sportswear, strategy, style, subsidization, subsidy,
   subvention, supply, supplying, tactics, thirds, threads, togs,
   toilette, trim, venture, vertical envelopment, vestment, vesture,
   victualing, wear, wearing apparel