Was a bit of a terror, and dissolute (6)
I believe the answer is:
waster
'was a bit of a terror and dissolute' is the definition.
I can't judge whether this definition defines the answer.
'was a bit of a terror and dissolute' is the wordplay.
'a bit of' says to take the initial letters.
'and' means one lot of letters go next to another.
'dissolute' becomes 'er' (I am not sure about this - if you are sure you should believe this answer much more).
The initial letter of 'terror' is 't'.
'was'+'t'+'er'='WASTER'
Can you help me to learn more?
(Other definitions for waster that I've seen before include "Useless person, good-for-nothing" , "Idler, good-for-nothing" , "Layabout" , "Person doing nothing of value (colloq.)" , "Ne'er do well, profligate" .)