The Collaborative International Dictionary of English v.0.48:

Subvention \Sub*ven"tion\, n. [F., fr. LL. subventio, fr. L.
   subvenire to come up to one's assistance, to assist. See
   Souvenir, and cf. Subvene.]
   1. The act of coming under. "The subvention of a cloud."
      --Stackhouse.
      [1913 Webster]

   2. The act of relieving, as of a burden; support; aid;
      assistance; help.
      [1913 Webster]

   3. A government aid or bounty.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Subvention \Sub*ven"tion\, v. t.
   To subventionize.
   [1913 Webster]

WordNet (r) 3.0 (2006):

subvention
    n 1: grant of financial aid as from a government to an
         educational institution
    2: the act or process of providing aid or help of any sort
    v 1: guarantee financial support of; "The opera tour was
         subvented by a bank" [syn: underwrite, subvention,
         subvent]