Source : Webster's Revised Unabridged Dictionary (1913)

Natty \Nat"ty\, a. [Cf. {Neat} clean.]
   Neat; tidy; spruce. [Colloq.] -- {Nat"ti*ly}, adv. --
   {Nat"ti*ness}, n.

Source : WordNet®

nattily
     adv : in a natty manner; with smartness; "it was arranged
           carefully and nattily"