Sort of measure that's beyond Department G (5)
I believe the answer is:
depth
'g' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'sort of measure that's beyond department' is the wordplay.
'sort of measure' becomes 'H'.
'that's beyond' means one lot of letters go next to another.
'department' becomes 'dept'.
'h' after 'dept' is 'DEPTH'.
Can you help me to learn more?
(Other definitions for depth that I've seen before include "Measurement from front to back" , "Deepness" , "Downward extent" , "Military life; vulgarly artificial" , "Profoundness" .)