The Collaborative International Dictionary of English v.0.48:

Fusiform \Fu"si*form\, a. [L. fusus spindle + -form: cf. F.
   fusiforme.]
   Shaped like a spindle; shaped like a cylinder that tapers at
   each end; as, a fusiform root; a fusiform cell.

   Syn: cigar-shaped. [1913 Webster]

WordNet (r) 3.0 (2006):

fusiform
    adj 1: tapering at each end [syn: fusiform, spindle-shaped,
           cigar-shaped]