Copy it in a mite shakily (7)
I believe the answer is:
imitate
'copy' is the definition.
(I know that copy is a is a more specific form of the action of imitate)
'it in a mite shakily' is the wordplay.
'in' indicates putting letters inside.
'shakily' is an anagram indicator.
'a'+'mite'='amite'
'amite' with letters rearranged gives 'imate'.
'it' put within 'imate' is 'IMITATE'.
(Other definitions for imitate that I've seen before include "Mimic or follow as a model" , "Parrot" , "Reproduce" , "I ate Tim! (anag.)" , "Copy someone" .)