Careful bosses keeping note of liabilities (8)
I believe the answer is:
studious
'careful' is the definition.
(similar in meaning)
'bosses keeping note of liabilities' is the wordplay.
'bosses' becomes 'studs' (boss can mean a type of metal stud).
'keeping' indicates putting letters inside (some letters kept inside).
'note of liabilities' becomes 'iou' (I can't justify this - if you can you should give a lot more credence to this answer).
'studs' enclosing 'iou' is 'STUDIOUS'.
Can you help me to learn more?
(Other definitions for studious that I've seen before include "showing diligence" , "Diligent, assiduous" , "Like a good schoolboy" , "with great care" , "Academic, diligent" .)