Special valour, ousting a tyrant (7)
I believe the answer is:
scourge
'tyrant' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'special valour ousting a' is the wordplay.
'special' becomes 'S' (common abbreviation as in Special Air Service).
'valour' becomes 'courage' (I've seen this before).
'ousting' indicates named letters should be taken away.
'courage' with 'a' taken away is 'courge'.
's'+'courge'='SCOURGE'
Can you help me to learn more?
(Other definitions for scourge that I've seen before include "Harass" , "One causing great suffering; whip" , "Person/thing causing great suffering; whip" , "Flog, punish" , "Punish severely" .)