Great dress on the end is fashionable, giving rise to envy, for instance (6,3)
I believe the answer is:
deadly sin
'envy for instance' is the definition.
(I know that envy is a type of deadly sin)
'great dress on the end is' is the wordplay.
'great' becomes 'deadly' (I can't explain this - if you can you should believe this answer much more).
'dress' is an anagram indicator (dress or prepare the letters).
'the end' says to take the final letters.
The final letter of 'on' is 'n'.
'n'+'is'='nis'
'nis' with letters rearranged gives 'sin'.
'deadly'+'sin'='DEADLY SIN'
'fashionable giving rise to' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for deadly sin that I've seen before include "a cause of damnation" , "Eg, lust or gluttony" , "Anger, covetousness, envy, gluttony, lust, pride or sloth" , "Greed, perhaps" , "Anger, say" .)