Really ? I thought « Elle est bonne » meant precisely that. So « bonnasse » would logically be the same, but... worse.
Elle est "bonne" is a very (intentionally) ambiguous expression in French, just like you'd say in English: That's a good one!
You could then use it to say:
- Elle est bonne (cette bière) to signify that it's a good brand.
- Elle est bonne (cette bière) to signify that it's at the right temperature.
- Elle est bonne (cette bière) to signify that it came on time, because you're thirsty, or the weather is hot, etc.
- Elle est bonne (cette anecdote) to signify that it's a good joke.
- Elle est bonne (cette petite) to signify that she's a good student.
- Elle est bonne (cette fille) to signify that she's a nice lay.
This makes the term usable for objects and people in a variety of situations, the ambiguity allowing the listener imagination to run wild.
(Bonasse) - I still insist - is pejorative and only applies to people.
