Vehicle for hire turning up at times on island (4)
I believe the answer is:
taxi
'vehicle for hire' is the definition.
(I've seen this before)
'turning up at times on island' is the wordplay.
'turning up' is a reversal indicator.
'times' becomes 'x' (multiplication sign).
'on' says to put letters next to each other.
'island' becomes 'i'.
'at' in reverse letter order is 'ta'.
'ta'+'x'+'i'='TAXI'
(Other definitions for taxi that I've seen before include "Hackney carriage" , "(Of a plane) move slowly on the ground" , "use apron" , "Prepare to take off" , "Vehicle with a meter" .)