The Collaborative International Dictionary of English v.0.48:

Amoebiform \A*m[oe]"bi*form\, Amoeboid \A*m[oe]"boid\, a.
   [Am[oe]ba + -form or -oid.] (Biol.)
   Resembling an am[oe]ba; am[oe]ba-shaped; changing in shape
   like an am[oe]ba.
   [1913 Webster]

   Am[oe]boid movement, movement produced, as in the am[oe]ba,
      by successive processes of prolongation and retraction.
      [1913 Webster]

WordNet (r) 3.0 (2006):

amoeboid
    adj 1: like an amoeba (especially in having a variable irregular
           shape) [syn: ameboid, amoeboid]