Kind ecologist on descending (5)
I believe the answer is:
genre
'kind' is the definition.
(I know that genre is a type of kind)
'ecologist on descending' is the wordplay.
I cannot really understand how this works, but
'on' could be 're' ('on' can be mean 'with reference to') and 're' is found within the answer.
The remaining letters 'gen' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for genre that I've seen before include "Type or style, of art" , "Style of work" , "Particular style of art or literature, may be green" , "expressive style of music" , "Artistic or literary category" .)