intromittent

from The Collaborative International Dictionary of English v.0.48

Intromittent \In`tro*mit"tent\, a. [L. intromittens, p. pr.]
   [1913 Webster]
   1. Throwing, or allowing to pass, into or within.
      [1913 Webster]

   2. (Zool.) Used in copulation; -- said of the external
      reproductive organs of the males of many animals, and
      sometimes of those of the females.
      [1913 Webster]