Flag is recognised international symbol for starters (4)
I believe the answer is:
iris
'flag' is the definition.
(type of iris flower)
'is recognised international symbol for starters' is the wordplay.
'for starters' indicates taking the first letters.
The first letters of 'is recognised international symbol' is 'IRIS'.
(Other definitions for iris that I've seen before include "Bright flower or eye part" , "Pupil's place?" , "Eye part or pretty flower" , "--- Murdoch, author" , "Flag - surrounding pupil" .)