natty, orderly, spruce, trim.

That which is _clean_ is simply free from soil or defilement of any
kind. Things are _orderly_ when in due relation to other things; a room
or desk is _orderly_ when every article is in place; a person is
_orderly_ who habitually keeps things so. _Tidy_ denotes that which
conforms to propriety in general; an unlaced shoe may be perfectly
_clean_, but is not _tidy_. _Neat_ refers to that which is _clean_ and
_tidy_ with nothing superfluous, conspicuous, or showy, as when we speak
of plain but _neat_ attire; the same idea of freedom from the
superfluous appears in the phrases "a _neat_ speech," "a _neat_ turn,"
"a _neat_ reply," etc. A _clean_ cut has no ragged edges; a _neat_
stroke just does what is intended. _Nice_ is stronger than _neat_,
implying value and beauty; a _cheap_, coarse dress may be perfectly
_neat_, but would not be termed _nice_. _Spruce_ is applied to the show
and affectation of neatness with a touch of smartness, and is always a
term of mild contempt; as, a _spruce_ serving man. _Trim_ denotes a
certain shapely and elegant firmness, often with suppleness and grace;
as, a _trim_ suit; a _trim_ figure. _Prim_ applies to a precise, formal,
affected nicety. _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.

Antonyms:

dirty, negligent, slouchy, uncared for,
disorderly, rough, slovenly, unkempt,
dowdy, rude, soiled, untidy.

* * * * *

NECESSARY.

Synonyms:

essential, infallible, required, unavoidable,
indispensable, needed, requisite, undeniable.
inevitable, needful,

That is _necessary_ which must exist, occur, or be true; which in the
nature of things can not be otherwise. That which is _essential_ belongs
to the essence of a thing, so that the thing can not exist in its
completeness without it; that which is _indispensable_ may be only an
adjunct, but it is one that can not be spared; vigorous health is
_essential_ to an arctic explorer; warm clothing is _indispensable_.
That which is _requisite_ (or _required_) is so in the judgment of the
person requiring it, but may not be so absolutely; thus, the _requisite_
is more a matter of personal feeling than the _indispensable_.
_Inevitable_ (L. _in_