Briefly look for The Sun? (4)
I believe the answer is:
star
'the sun?' is the definition.
(sun is a kind of star)
'briefly look' is the wordplay.
'briefly' means to remove the last letter.
'look' becomes 'stare' (staring is a kind of looking).
'stare' with its final letter removed is 'STAR'.
'for' acts as a link.
(Other definitions for star that I've seen before include "eg The sun" , "A night light?" , "Brilliant person" , "Eg, Rigel, Aldebaran" , "For example, Marilyn Monroe" .)