Good to be in control for time as ruler (5)
I believe the answer is:
reign
'time as ruler' is the definition.
I can't tell whether this defines the answer.
'good to be in control' is the wordplay.
'good' becomes 'g' (abbreviation).
'to be in' means one lot of letters goes inside another.
'control' becomes 'rein' (reining is a kind of controlling).
'g' placed inside 'rein' is 'REIGN'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for reign that I've seen before include "Sovereignty" , "Wield the sceptre" , "Dominion" , "Occupy the throne" , "time in power" .)