This ruler won't give an inch (8)
I believe the answer is:
dictator
'this ruler' is the definition.
(dictator is a kind of ruler)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for dictator that I've seen before include "Hitler was one, like Stalin and Franco" , "One ordering" , "All-powerful ruler" , "Absolute ruler (Great in Chaplin film)" , "person in charge? Absolutely!" .)