Natty, a.
Etymology: [Cf. Neat clean.]
Neat; tidy; spruce. [Colloq.] -- Nat"ti*ly, adv. -- Nat"ti*ness, n.
Shades of meaning
Fernald has no entry of its own for natty; he lists it under neat.
Where he writes about it:
Dapper is spruce with the suggestion of smallness and slightness; natty, a diminutive of neat, suggests minute elegance, with a tendency toward the exquisite; as, a dapper little fellow in a natty business suit. — from neat