WordNet (r) 3.0 (2006):

reserves
    n 1: civilians trained as soldiers but not part of the regular
         army [syn: militia, reserves]

Moby Thesaurus II by Grady Ward, 1.0:

127 Moby Thesaurus words for "reserves":
   Swiss bank account, US Army Reserve, US Naval Reserve, agent,
   alternate, alternative, analogy, army reserves, assets,
   auxiliaries, backlog, backup, balance, bank account, bottom dollar,
   budget, cache, cash reserves, cast, change, changeling,
   checking account, command of money, company, comparison,
   complement, copy, counterfeit, crew, deputy, double, dummy, eight,
   eleven, equal, equivalent, ersatz, exchange, exchequer, fake,
   fill-in, finances, first string, first team, five, fund, funds,
   ghost, ghostwriter, home defense army, home reserves, imitation,
   kitty, landwehr, life savings, locum tenens, makeshift, means,
   metaphor, metonymy, moneys, nest egg, next best thing, nine,
   organized reserves, pecuniary resources, personnel, phony,
   pinch hitter, platoon, pocket, pool, proxy, purse, reinforcements,
   relief, replacement, representative, reserve, reserve forces,
   reserve fund, reserve supply, reservoir, resource, resources,
   ringer, rowing crew, savings, savings account, second string,
   second team, secondary, sign, sinking fund, something in reserve,
   spares, squad, stand-in, stockpile, string, sub, substance,
   substituent, substitute, substitution, succedaneum, superseder,
   supplanter, supplementary reserves, support, surrogate, symbol,
   synecdoche, team, territorial reserves, third string, token,
   treasure, understudy, unexpended balance,
   unregistered bank account, utility player, varsity, vicar,
   vice-president, vice-regent, wherewithal