Discipline Conservative and hurry up about it! (7)
I believe the answer is:
chasten
'discipline' is the definition.
(I've seen this before)
'conservative and hurry up about it' is the wordplay.
I cannot really understand how this works, but
'conservative' could be 'c' (UK political abbreviation) and 'c' is present in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is found within the answer.
'hurry' could be 'haste' (haste is hurrying or rushing) and 'haste' is found within the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for chasten that I've seen before include "Subdue - a stench (anag)" , "Castigate or punish" , "Moderate" , "Humble" , "Punish, purify" .)