The Collaborative International Dictionary of English v.0.48:

Suspensor \Sus*pen"sor\, n. [NL.]
   1. A suspensory.
      [1913 Webster]

   2. (Bot.) The cord which suspends the embryo; and which is
      attached to the radicle in the young state; the proembryo.
      [1913 Webster]

WordNet (r) 3.0 (2006):

suspensor
    n 1: a support for the genitals worn by men engaging in
         strenuous exercise [syn: athletic supporter, supporter,
         suspensor, jockstrap, jock]