A craftsman, we declare! (6)
I believe the answer is:
weaver
'a craftsman' is the definition.
(weaver is a kind of craftsman)
'we declare' is the wordplay.
'declare' becomes 'aver' (averring is a kind of declaring).
'we'+'aver'='WEAVER'
(Other definitions for weaver that I've seen before include "A craftsman" , "Bottom was one (MND)" , "Bottom's trade (MND)" , "Maker of baskets" , "Bottom's trade in A M N D" .)