Selfish about pixie (3)
I believe the answer is:
elf
'pixie' is the definition.
(synonyms)
'selfish about' is the wordplay.
'about' says the answer is hidden in the clue (the clue goes around or about the answer).
'ELF' can be found hidden inside 'selfish'.
(Other definitions for elf that I've seen before include "Mischievous creature" , "Pixie (able to cobble?)" , "Santa's helper" , "A small sprite with magic powers" , "German team?" .)