Uncover second butterfly in centre of sand hills (9)
I believe the answer is:
unsheathe
'uncover' is the definition.
(thesaurus)
'second butterfly in centre of sand hills' is the wordplay.
'second butterfly' becomes 'sheath' (I can't justify this - if you can you should believe this answer much more).
'in' indicates putting letters inside.
'centre of' means to look at the middle letters.
'sand hills' becomes 'dunes' (I've seen this before).
The middle letters of 'dunes' are 'une'.
'sheath' inserted within 'une' is 'UNSHEATHE'.
Can you help me to learn more?
(Other definitions for unsheathe that I've seen before include "Draw (a sword)" , "Pull out (a blade)" , "Draw out (a knife)" , "Remove from cover like sword" , "Take out of scabbard" .)