Killer in wood, wife smiled devilishly in repose (5,3,7)
I believe the answer is:
dutch elm disease
'killer in wood' is the definition.
'dutch elm disease' can be an answer for 'killer' (I've seen this before). I'm unsure of the 'in wood' bit.
'wife smiled devilishly in repose' is the wordplay.
I cannot quite understand how this works, but
'wife' could be 'dutch' (slang term) and 'dutch' is found within the answer.
an anagram of 'smiled' is 'elmdis' which is within the answer.
'repose' could be 'ease' (synonyms) and 'ease' is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for dutch elm disease that I've seen before include "a growing problem" , "threat to the forest" , "Fungal tree ailment" , "tree problem" , "Killer" .)