Still getting letters from Stevenson (4,2)
I believe the answer is:
even so
'still' is the definition.
(both can mean 'nonetheless')
'letters from stevenson' is the wordplay.
'letters from' indicates a hidden word (a selection of letters from the clue).
'EVEN SO' can be found hidden inside 'stevenson'.
'getting' is the link.
(Other definitions for even so that I've seen before include "however" , "'Nevertheless (4,2)'" , "yet" , "in any event" , "Notwithstanding" .)