Imperil young Daniel in green mix (8)
I believe the answer is:
endanger
'imperil' is the definition.
(synonyms)
'young daniel in green mix' is the wordplay.
'young daniel' becomes 'dan' (I am not sure about this - if you are sure you should believe this answer much more).
'in' is an insertion indicator.
'mix' indicates an anagram.
'green' with letters rearranged gives 'enger'.
'dan' put within 'enger' is 'ENDANGER'.
Can you help me to learn more?
(Other definitions for endanger that I've seen before include "Expose to injury or extinction" , "Put in peril" , "Imperil" , "Threaten" , "Put in trouble" .)