The Collaborative International Dictionary of English v.0.48:

Aggroup \Ag*group"\, v. t. [imp. & p. p. Aggrouped; p. pr. &
   vb. n. Aggrouping.] [F. agrouper; [`a] (L. ad) + groupe
   group. See Group..]
   To bring together in a group; to group. --Dryden.
   [1913 Webster]