APPOSE is a 6 letter word that starts with A.

1. \Ap*pose"\, v. t. [F. apposer to set to; ? (L. ad) +
   poser to put, place. See {Pose}.]
   1. To place opposite or before; to put or apply (one thing to
      another).
            The nymph herself did then appose, For food and
            beverage, to him all best meat.       --Chapman.
   2. To place in juxtaposition or proximity.
   

2. \Ap*pose"\, v. t. [For oppose. See {Oppose}.]
   To put questions to; to examine; to try. [Obs.] See {Pose}.
         To appose him without any accuser, and that secretly.
                                                  --Tyndale.