Source : Webster's Revised Unabridged Dictionary (1913)

Equitably \Eq"ui*ta*bly\, adv.
   In an equitable manner; justly; as, the laws should be
   equitably administered.

Source : WordNet®

equitably
     adv : in an equitable manner; "the inheritance was equitably
           divided among the sisters" [ant: {inequitably}]