The Collaborative International Dictionary of English v.0.48:

Spermatozoid \Sper`ma*to*zo"id\, n. [Spermatozoon + Gr. e'i^dos
   form.] (Biol.)
   The male germ cell in animals and plants, the essential
   element in fertilization; a microscopic animalcule-like
   particle, usually provided with one or more cilia by which it
   is capable of active motion. In animals, the familiar type is
   that of a small, more or less ovoid head, with a delicate
   threadlike cilium, or tail. Called also spermatozoon. In
   plants the more usual term is antherozoid.
   [1913 Webster]

WordNet (r) 3.0 (2006):

spermatozoid
    n 1: a motile male gamete of a plant such as an alga or fern or
         gymnosperm [syn: antherozoid, spermatozoid]