Wander over island for the language? (5)
I believe the answer is:
maori
'the language?' is the definition.
(Maori is an example)
'wander over island' is the wordplay.
'wander' becomes 'roam' (synonyms).
'over' says the letters should be written in reverse.
'island' becomes 'i' (geographical abbreviation).
'roam' back-to-front is 'maor'.
'maor'+'i'='MAORI'
'for' acts as a link.
(Other definitions for maori that I've seen before include "Let it stand" , "Native of New Zealand and the Cook Islands" , "Original New Zealanders" , "native person" , "One of New Zealand's aboriginal people" .)