Gershwin say in restaurant asking for starters (3)
I believe the answer is:
ira
'gershwin' is the definition.
(lyricist Ira Gershwin, brother of George)
'in restaurant asking for starters' is the wordplay.
'for starters' indicates taking the first letters.
The initial letters of 'in restaurant asking' is 'IRA'.
'say' is the link.
(Other definitions for ira that I've seen before include "Militant republicans" , "terrorists" , "George 13 down's brother" , "George Gershwin's older brother, the lyricist" , "Songwriter George's elder brother" .)