Ring up to import island flower (5)
I believe the answer is:
lilac
'flower' is the definition.
(I've seen this before)
'ring up to import island' is the wordplay.
'ring' becomes 'call' (call on the phone).
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'to import' indicates putting letters inside.
'island' becomes 'i' (geographical abbreviation).
'call' reversed gives 'llac'.
'llac' going around 'i' is 'LILAC'.
(Other definitions for lilac that I've seen before include "Shade" , "Pale violet hue" , "Light-purple" , "Shrub with fragrant pink, purple or white flowers" , "Drop by about one, turning" .)