Crossword Genius

The height a bet can go up to (4)

Ross

I believe the answer is:

etna

I'm a little stuck... Click here to teach me more about this clue!

'the height' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.

I can't explain the remainder of the clue.

Can you help me to learn more?

(Other definitions for etna that I've seen before include "Neat kind of European volcano" , "Europe's highest active volcano" , "source of fumes?" , "Volcanic mount in Sicily" , "Volcano in Sicily, quite neat" .)

I've seen this clue in the Evening Standard.
Want a hint initially instead of a full solution? Install my app