The Collaborative International Dictionary of English v.0.48:

Alliterative \Al*lit"er*a*tive\ (?; 277), a.
   Pertaining to, or characterized by, alliteration; as,
   alliterative poetry. -- Al*lit"er*a*tive*ly, adv. --
   Al*lit"er*a*tive*ness, n.
   [1913 Webster]