Head of Anatomy Department eviscerated lamprey with skill (7)
I believe the answer is:
adeptly
'with skill' is the definition.
(I've seen this in another clue)
'head of anatomy department eviscerated lamprey' is the wordplay.
'head of' suggests taking the first letters.
'department' becomes 'dept'.
'eviscerated' means to remove the middle letters (the word is disembowelled of its inside letters).
'lamprey' with its middle taken out is 'ly'.
The first letter of 'anatomy' is 'a'.
'a'+'dept'+'ly'='ADEPTLY'
(Other definitions for adeptly that I've seen before include "Showing skill" , "with great skill" , "How experts act" , "Adroitly" , "Skilfully" .)