Is his power of command all over? (7)
I believe the answer is:
general
'is his power of command all over?' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
This is the entire clue.
Can you help me to learn more?
(Other definitions for general that I've seen before include "Of wide application" , "Not specialised, like army chief" , "Common - soldier" , "Not specialised or limited" , "Senior military officer" .)