College spread out in sea islands (9)
I believe the answer is:
polynesia
'islands' is the definition.
(I know that Polynesia is a islands)
'college spread out in sea' is the wordplay.
'college' becomes 'poly' (polytechnic).
'spread out' indicates anagramming the letters (I've seen 'spreading out' mean this).
'in'+'sea'='insea'
'insea' with letters rearranged gives 'nesia'.
'poly'+'nesia'='POLYNESIA'
(Other definitions for polynesia that I've seen before include "Antipodeans around here" , "Pacific island group" , "Pacific islands incl. N Zealand, Samoa and Hawaii" , "Pacific region?" , "Islands including Hawaii, Tonga, Samoa, etc." .)