Sold it off, being dependable (6)
I believe the answer is:
stolid
'being dependable' is the definition.
(I've seen this before)
'sold it off' is the wordplay.
'off' is an anagram indicator.
'sold'+'it'='soldit'
'soldit' is an anagram of 'STOLID'.
(Other definitions for stolid that I've seen before include "Difficult to excite, apathetic" , "Not excitable or emotional" , "Hard to excite" , "with a stiff upper lip" , "displaying little emotion" .)