A snooty sort erected current plant (6)
I believe the answer is:
bonsai
'plant' is the definition.
The answer is an example.
'a snooty sort erected current' is the wordplay.
'snooty sort' becomes 'snob' (snob can mean a snooty person).
'erected' says the letters should be written backwards (in a down clue, letters go up).
'current' becomes 'I' (symbol for electric current).
'a'+'snob'='asnob'
'asnob' reversed gives 'bonsa'.
'bonsa'+'i'='BONSAI'
(Other definitions for bonsai that I've seen before include "(Cultivation of) dwarf trees" , "Little plants" , "Art of dwarfing trees" , "Art of dwarfing shrubs" , "Small tree" .)