Rule that holds George initially in check (5)
I believe the answer is:
reign
'rule that holds' is the definition.
'reign' can be an answer for 'rule' (reign is a kind of rule). I am unsure of the rest of the definition.
'george initially in check' is the wordplay.
'initially' suggests taking the first letters.
'in' indicates putting letters inside.
'check' becomes 'rein' (both can mean to control or limit).
The first letter of 'george' is 'g'.
'g' put inside 'rein' is 'REIGN'.
Can you help me to learn more?
(Other definitions for reign that I've seen before include "Monarch's time in the job" , "Hold sway, rule" , "Sovereignty" , "Rule - dominate" , "are unbeatable!" .)