Tumbles over the coal scuttle - how careless! (8)
I believe the answer is:
slipshod
'careless' is the definition.
(similar in meaning)
'tumbles over the coal scuttle' is the wordplay.
'tumbles over' becomes 'slips' (I can't justify this - if you can you should give a lot more credence to this answer).
'the coal scuttle' becomes 'hod' (I've seen this in another clue).
'slips'+'hod'='SLIPSHOD'
'how' is the link.
Can you help me to learn more?
(Other definitions for slipshod that I've seen before include "Sloppy and haphazard" , "Lacking in care" , "Careless and slapdash, bad work" , "Inattentive" , "Sloppy, careless" .)