Brown back in time to be descended on the male side (6)
I believe the answer is:
agnate
'be descended on the male side' is the definition.
I can't judge whether this definition defines the answer.
'brown back in time' is the wordplay.
'brown' becomes 'tan' (tan is a kind of brown).
'back' shows that the letters should be reversed in order.
'in' is an insertion indicator.
'time' becomes 'age' (age is a kind of time).
'tan' backwards is 'nat'.
'nat' placed into 'age' is 'AGNATE'.
'to' is the link.
Can you help me to learn more?
(Other definitions for agnate that I've seen before include "Descended from the same male ancestor" , "Relative" , "Related through male descent on father's side (6)" , "Get an A (anag.)" .)