Proxima Centauri, for one (4)
I believe the answer is:
star
'proxima centauri for one' is the definition.
(proxima centauri is a kind of star)
This is all the clue.
(Other definitions for star that I've seen before include "The leading player is heavenly" , "personality?" , "Lead actor" , "Point of light in the heavens" , "Pointed symbol" .)