Giant island acquires a queen (7)
I believe the answer is:
titania
'queen' is the definition.
(fairy queen)
'giant island acquires a' is the wordplay.
'giant' becomes 'titan' (titans are giant mythological creatures).
'island' becomes 'i' (geographical abbreviation).
'acquires' says to put letters next to each other.
'titan'+'i'+'a'='TITANIA'
(Other definitions for titania that I've seen before include "Queen of fairyland" , "Shakespeare's queen of the fairies" , "Queen of the fairies - Uranus satellite" , "Bottom fan" , "Fairy queen (AMND)" .)