Shakespeare's wife knows how! (8)
I believe the answer is:
hathaway
'shakespeare's wife' is the definition.
'hathaway' can be an answer for 'wife' (I have seen 'Celebrated wife' mean 'hathaway' so perhaps 'wife' could also mean 'hathaway'). I'm not certain of the 'shakespeare's' bit.
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for hathaway that I've seen before include "Anne ---, married Shakespeare" , "See 7" , "Shakespearean woman!" , "Anne --, the Bard's wife" , "Surname of Shakespeare's wife" .)