॥ श्री राम ॥
Rām-Rām Nathan,

निराला is primarily “apart”, “distinct”, “special”, “unique”, coming from the Sanskrit √आली, meaning “to come close to”, and thus referring (originally) to a place. With the famed Hindi poet surnamed “निराला”, it meant unique –as no one comes close to him, so great was his talent. So “wonderful” doesn’t quite cut it.

ख़ास/ خاص is the Arabic equivalent denoting being distinguished (from others), hence of choice quality. [And, without the nukta, खास/ کهاس khās, it means a burlap sack–of course, you can always add “filled with sugar”.

As for “incomplete”, अपूर्ण might be another, if not better, choice. अधूरा has nothing to do with धूरा, dust, trick, deception, but from the Sanskrit अर्ध + पूर + क, meaning half-formed, as an embryo in a miscarriage. Of course, very few spouses are etymologists to pick up on these vibes.*

And so it goes…

*Also, but much less common, we have असिद्ध (unaccomplished), असमाप्त / असंपूर्ण / बेतमाम (incomplete), (unaccomplished), अनिर्वृत्त (unfulfilled), and निरर्थक (meaningless).