Source : Webster's Revised Unabridged Dictionary (1913)

Gainly \Gain"ly\, adv. [See {Gain}, a.]
   Handily; readily; dexterously; advantageously. [Obs.] --Dr.
   H. More.

Source : WordNet®

gainly
     adj : graceful and pleasing; "gainly conduct"; "a gainly youth
           with dark hair and eyes"