Special
Unique
noun, な adjective, の adjective
An especially special thing is even more special and probably a lot more unique than ordinary special things.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
この車のタイヤはちょっと特殊なんだよ。
This car’s tires are pretty unique.