Derivation (6)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
origin
'derivation' is the definition.
(I know that origin is a type of derivation)
This is all the clue.
(Other definitions for origin that I've seen before include "Where axes cut" , "Place or point of beginning (6)" , "Crossing of axes" , "Source, root" , "Source, derivation" .)