1. 想要成为的；可能成为的
You use prospective to describe someone who wants to be the thing mentioned or who is likely to be the thing mentioned.

2. 可能即将发生的
You use prospective to describe something that is likely to happen soon.

1. of or concerned with or related to the future

e.g. prospective earnings
a prospective mother
a prospective bride
the statute is solely prospective in operation