scivolema

Take it apart and it explains itself. Scii is to know, voli is to want, so scivoli is to want to know. Add -em-, the suffix for a settled disposition, and -a for the adjective, and you have someone whose standing character is wanting to know. Four pieces, no borrowing, and a word an English speaker has to be told rather than shown.

The pair with scivola is the whole point of the -em-. Scivola is curious about something in particular, right now: mi estas scivola pri via respondo. Scivolema is curious as a personality trait, which is why it drifts towards English nosy when the speaker disapproves. It is the difference between wanting to know one thing and being the sort of person who always wants to know.

And keep both away from kurioza, which does not mean this at all. Esperanto's kurioza covers only the half of English curious that means odd or strange, and the Reta Vortaro goes as far as printing an instruction telling readers not to use it for scivola. The full set of these traps is collected in Falsaj amikoj, where this pair is one of the three the article says you must learn today.