Source : Webster's Revised Unabridged Dictionary (1913)

Imparipinnate \Im*par"i*pin"nate\, a. [L. impar unequal + E.
   pinnate.] (Bot.)
   Pinnate with a single terminal leaflet.

Source : WordNet®

imparipinnate
     adj : a leaf shape; pinnate with a single leaflet at the apex
           [syn: {odd-pinnate}]