不悪[ashikarazu] don't get me wrong, but ...
意識不明[ishikifumei] unconscious
一心不乱[isshinfuran] wholeheartedly
一定不変[itteifuhen] invariable
運動不足[undoubusoku] insufficient exercise

栄養不足[eiyoubusoku] malnutrition
過不足[kafusoku] excess or deficiency
回復不可能[kaifukufukanou] non-recoverable
気不味い[kimazui] unpleasant
健康不安[kenkoufuan] poor health

黒銹病[kurosabibyou] black rust
不銹鋼[fushuukou] stainless steel
防銹[boushuu] anti-rust

銹病[sabibyou] (plant) rust
銹菌[sabikin] rust (fungus)

圧延鋼[atsuenkou] rolled steel
丸鋼[marukou] round steel bar
協力鋼[kyouryokukou] high-tension steel
鋼管[koukan] steel pipe
鋼玉[kougyoku] corundum

鋼材[kouzai] steel material
鋼索[kousaku] cable
鋼線[kousen] steel wire
鋼鉄[koutetsu] steel