Laid-back fan (4)
I believe the answer is:
cool
I believe this is a double definition.
'laid-back' is the first definition.
(cool can mean laid-back or calm)
'fan' is the second definition.
(fan can mean to keep cool)
(Other definitions for cool that I've seen before include "Not keen!" , "Moderately cold" , "Fashionable (but don't lose yours!)" , "Calm and unemotional" , "Calm and collected" .)