The Collaborative International Dictionary of English v.0.48:

Accouple \Ac*cou"ple\, v. t. [OF. acopler, F. accoupler. See
   Couple.]
   To join; to couple. [R.]
   [1913 Webster]

         The Englishmen accoupled themselves with the Frenchmen.
                                                  --Hall.
   [1913 Webster]

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

ACCOUPLE. To accouple is to marry. See Ne unquas accouple.