Source : Webster's Revised Unabridged Dictionary (1913)

Zoodendrium \Zo`["o]*den"dri*um\, n.; pl. {Zo["o]dendria}. [NL.,
   fr. Gr. zw^,on an animal + ? a tree.] (Zo["o]l.)
   The branched, and often treelike, support of the colonies of
   certain Infusoria.