College in sea, around some islands (9)
I believe the answer is:
polynesia
'some islands' is the definition.
(I've seen this before)
'college in sea around' is the wordplay.
'college' becomes 'poly' (polytechnic).
'around' indicates an anagram.
'in'+'sea'='insea'
'insea' anagrammed gives 'nesia'.
'poly'+'nesia'='POLYNESIA'
(Other definitions for polynesia that I've seen before include "large group of islands" , "Extensive group of Pacific islands" , "Antipodeans around here" , "Pacific island group" , "Pacific region?" .)