Female graduate touring island compound (7)
I believe the answer is:
alumina
'compound' is the definition.
(chemical compound)
'female graduate touring island' is the wordplay.
'female graduate' becomes 'alumna' (I've seen this before).
'touring' means one lot of letters goes inside another (touring can mean going round).
'island' becomes 'i' (geographical abbreviation).
'alumna' enclosing 'i' is 'ALUMINA'.
(Other definitions for alumina that I've seen before include "Compound in many clays" , "emery" , "Substance of sapphire" , "Constituent of sapphire" , "Oxide in corundum" .)