Noun
のろい
魔女はお姫様に、コップを逆さまにしか持てなくする呪いをかけた。
The witch put a curse on the princess that made it so she could only hold cups upside down.
Despite looking like an adjective this is a noun. It means the same thing as the kanji: curse.
The reading is the same as the reading you learned with the kanji.