Relative from Amsterdam, perhaps one giving firm but benevolent advice (5,5)
I believe the answer is:
dutch uncle
'one giving firm but benevolent advice' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'relative from amsterdam perhaps' is the wordplay.
I cannot really see how this works, but
'relative' could be 'uncle' (uncle is a kind of relative) and 'uncle' is present in the answer.
The remaining letters 'dutch' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for dutch uncle that I've seen before include "Severe critic" , "one giving a right earful" , "One firmly but kindly advising" , "who speaks frankly?" , "Someone giving firm and frank but good advice" .)