what is just wonder or just curious in Japanese
 

i ask my friend some words and she ask me back
"u found this word in your textbook?"
i wanna say like "no, im just wonder or just curious"

Probably something like ただ、きょうみがあるだけです would be OK.

「いいえ、ただの興味（きょうみ）です。」 sounds more natural.

「いいえ、たまたま読んだ（よんだ）のです。」 would also work. (No, I just happened to read it.)　

or

「いいえ、たまたま見つけた（みつけた）のです。」　 (No, I just happened to come across it.)

got that thank you very much