First to sell plough, for all that (5)
I believe the answer is:
still
'for all that' is the definition.
(I've seen this before)
'first to sell plough' is the wordplay.
'first to' indicates taking the first letters.
'plough' becomes 'till' (I've seen this before).
The initial letter of 'sell' is 's'.
's'+'till'='STILL'
(Other definitions for still that I've seen before include "inaudible" , "Static photograph" , "source of spirits" , "Stationary" , "not bubbly" .)