The Collaborative International Dictionary of English v.0.48:

Espouse \Es*pouse"\, v. t. [imp. & p. p. Espoused; p. pr. &
   vb. n. Espousing.] [OF. espouser, esposer, F. ['e]pouser,
   L. sponsare to betroth, espouse, fr. sponsus betrothed, p. p.
   of spondere to promise solemnly or sacredly. Cf. Spouse.]
   1. To betroth; to promise in marriage; to give as spouse.
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            A virgin espoused to a man whose name was Joseph.
                                                  --Luke i. 27.
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   2. To take as spouse; to take to wife; to marry.
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            Lavinia will I make my empress, . . .
            And in the sacred Pantheon her espouse. --Shak.
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   3. To take to one's self with a view to maintain; to make
      one's own; to take up the cause of; to adopt; to embrace.
      "He espoused that quarrel." --Bacon.
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            Promised faithfully to espouse his cause as soon as
            he got out of the war.                --Bp. Burnet.
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WordNet (r) 3.0 (2006):

espouse
    v 1: choose and follow; as of theories, ideas, policies,
         strategies or plans; "She followed the feminist movement";
         "The candidate espouses Republican ideals" [syn: adopt,
         follow, espouse]
    2: take in marriage [syn: marry, get married, wed,
       conjoin, hook up with, get hitched with, espouse]
    3: take up the cause, ideology, practice, method, of someone and
       use it as one's own; "She embraced Catholicism"; "They
       adopted the Jewish faith" [syn: espouse, embrace,
       adopt, sweep up]