Order cuts always when mounting purge (6)
I believe the answer is:
remove
'purge' is the definition.
(thesaurus)
'order cuts always when mounting' is the wordplay.
I cannot quite understand how this works, but
'order' could be 'ove' and 'ove' is located in the answer.
The remaining letters 'rem' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for remove that I've seen before include "Eliminate" , "Takeaway" , "Get rid of, take away (6)" , "class in a number of schools" , "Take away from present place, or get rid of" .)