Pretentious person rejected excellent small plant (6)
I believe the answer is:
bonsai
'small plant' is the definition.
The answer and definition can be both plants as well as being singular nouns.
I also know that 'small' relates to this answer.
'pretentious person rejected excellent' is the wordplay.
'pretentious person' becomes 'snob' (I've seen this in another clue).
'rejected' says the letters should be written backwards.
'excellent' becomes 'ai' (resembles 'A1', old-fashioned term for excellent).
'snob' backwards is 'bons'.
'bons'+'ai'='BONSAI'
Can you help me to learn more?
(Other definitions for bonsai that I've seen before include "specimen with restricted roots?" , "Art of dwarfing trees" , "Japanese method of growing miniature plants" , "Bosnia (anag.)" , "Little Japanese growth" .)