Green dresses perfect ultimately for mother (6)
I believe the answer is:
native
'for mother' is the definition.
(as in a native or mother tongue)
'green dresses perfect ultimately' is the wordplay.
'green' becomes 'naive' (green can mean naive or innocent).
'dresses' indicates putting letters inside (dress can mean cover).
'perfect ultimately' becomes 't' (I can't explain this - if you can you should believe this answer much more).
'naive' going around 't' is 'NATIVE'.
Can you help me to learn more?
(Other definitions for native that I've seen before include "Resident" , "Belonging to one by birth" , "Endemic - aborigine" , "Indigenous, aboriginal" , "In a natural state" .)