Westward island volcanic eruption in which one's ready (9)
I believe the answer is:
available
'one's ready' is the definition.
'available' can be an answer for 'ready' (thesaurus). I am not certain of the 'one's' bit.
'westward island volcanic eruption in' is the wordplay.
'westward' says the letters should be written in reverse.
'island' becomes 'Bali' (Indonesian island).
'volcanic eruption' becomes 'avale' (I can't justify this - if you can you should believe this answer much more).
'in' indicates putting letters inside.
'bali' back-to-front is 'ilab'.
'ilab' going within 'avale' is 'AVAILABLE'.
'which' acts as a link.
Can you help me to learn more?
(Other definitions for available that I've seen before include "Able to be used, free" , "Not occupied, free" , "Obtainable or accessible" , "To hand" , "Unoccupied" .)