How do you spell petive?

"Petive" is not a standard English word. It's likely a misspelling of a word like:

* Petite: meaning small and dainty, often used to describe a person's size or build.

* Pettive: (though less common) meaning "petty" or "small-minded."

It's important to understand the context in which you encountered the word "petive" to determine the intended spelling.