The Collaborative International Dictionary of English v.0.48:

Capitalize \Cap"i*tal*ize\ (k[a^]p"[i^]*tal*[imac]z), v. t.
   [imp. & p. p. Capitalized (k[a^]p"[i^]*tal*[imac]zd); p.
   pr. & vb. n. Capitalizing.]
   1. To convert into capital, or to use as capital.
      [1913 Webster]

   2. To compute, appraise, or assess the capital value of (a
      patent right, an annuity, etc.)
      [1913 Webster]

   3. To print in capital letters, or with an initial capital.
      [1913 Webster]

   4. To supply capital for (an enterprise), especially by
      selling capital stock.
      [PJC]

WordNet (r) 3.0 (2006):

capitalize
    v 1: draw advantages from; "he is capitalizing on her mistake";
         "she took advantage of his absence to meet her lover" [syn:
         capitalize, capitalise, take advantage]
    2: supply with capital, as of a business by using a combination
       of capital used by investors and debt capital provided by
       lenders [syn: capitalize, capitalise]
    3: write in capital letters [syn: capitalize, capitalise]
    4: compute the present value of a business or an income [syn:
       capitalize, capitalise]
    5: consider expenditures as capital assets rather than expenses
       [syn: capitalize, capitalise]
    6: convert (a company's reserve funds) into capital [syn:
       capitalize, capitalise]

Moby Thesaurus II by Grady Ward, 1.0:

51 Moby Thesaurus words for "capitalize":
   aid, alphabet, alphabetize, angel, assist, back, balance,
   balance the books, bankroll, book, carry, carry over,
   cast up accounts, character, charge off, close out,
   close the books, credit, debit, docket, enter, finance, fund,
   grubstake, help, initial, inscribe, journalize, keep books, letter,
   log, make an entry, mark, minute, note, patronize, pay for, post,
   post up, promote, provide for, refinance, set up, sign, sponsor,
   stake, strike a balance, subsidize, support, transcribe,
   transliterate