Something that is desirable is worth having or doing because it is useful, necessary, or popular.
Prolonged negotiation was not desirable.
拖得很长的谈判是不受欢迎的。
Someone who is desirable is considered to be sexually attractive.
the young women of his own age whom his classmates thought most desirable.
与他同龄的、在他的同学们看来最性感的年轻女子。