The Collaborative International Dictionary of English v.0.48:

Geld \Geld\, n. [AS. gild, gield, geld, tribute, payment, fr.
   gieldan to pay, render. See Yield.]
   Money; tribute; compensation; ransom.[Obs.]
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   Note: This word occurs in old law books in composition, as in
         danegeld, or danegelt, a tax imposed by the Danes;
         weregeld, compensation for the life of a man, etc.
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The Collaborative International Dictionary of English v.0.48:

Geld \Geld\, v. t. [imp. & p. p. Gelded or Gelt (?); p. pr. &
   vb. n. Gelding.] [Icel. gelda to castrate; akin to Dan.
   gilde, Sw. g[aum]lla, and cf. AS. gilte a young sow, OHG.
   galt dry, not giving milk, G. gelt, Goth. gilpa siclke.]
   1. To castrate; to emasculate.
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   2. To deprive of anything essential.
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            Bereft and gelded of his patrimony.   --Shak.
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   3. To deprive of anything exceptionable; as, to geld a book,
      or a story; to expurgate. [Obs.] --Dryden.
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WordNet (r) 3.0 (2006):

geld
    v 1: cut off the testicles (of male animals such as horses);
         "the vet gelded the young horse" [syn: geld, cut]

Moby Thesaurus II by Grady Ward, 1.0:

18 Moby Thesaurus words for "geld":
   alter, castrate, change, demasculinize, desexualize, effeminate,
   effeminatize, effeminize, emasculate, eunuchize, fix, mutilate,
   neuter, sissify, soften, spay, unsex, womanize



Bouvier's Law Dictionary, Revised 6th Ed (1856):

GELD, old Eng. law. It signifies a fine or compensation for an offence;
also, rent, money or tribute.