Winged or wing-shaped (4)
I believe the answer is:
alar
This clue is a double definition.
'winged' is the first definition.
(similar in meaning)
'wing-shaped' is the second definition.
(synonyms)
(Other definitions for alar that I've seen before include "using such appendages to fly?" , "Related to wings" , "Like wings" , "Relating to wings" , "crop retardant" .)