Source : Webster's Revised Unabridged Dictionary (1913)

Morphologic \Mor`pho*log"ic\, Morphological \Mor`pho*log"ic*al\,
   a. [Cf. F. morphologique.] (Biol.)
   Of, pertaining to, or according to, the principles of
   morphology. -- {Mor`pho*log"ic*al*ly}, adv.

Source : WordNet®

morphologically
     adv : in a morphological manner; with regard to morphology; "these
           two words are morphologically related"