The Collaborative International Dictionary of English v.0.48:

Ament \Am"ent\, n. [L. amentum thong or strap.] (Bot.)
   A species of inflorescence; a catkin.
   [1913 Webster]

         The globular ament of a buttonwood.      --Coues.
   [1913 Webster]

WordNet (r) 3.0 (2006):

ament
    n 1: a cylindrical spikelike inflorescence [syn: catkin,
         ament]

Moby Thesaurus II by Grady Ward, 1.0:

34 Moby Thesaurus words for "ament":
   born fool, capitulum, catkin, clot, cone, congenital idiot, corymb,
   cretin, cyme, defective, golem, half-wit, head, idiot, imbecile,
   juggins, mongoloid idiot, moron, natural, natural idiot,
   natural-born fool, panicle, pine cone, raceme, simp, simpleton,
   spadix, spike, spikelet, strobile, thyrse, umbel, verticillaster,
   zany