Couple knocking swine about in book (7)
I believe the answer is:
twosome
'couple' is the definition.
(I know that couple can be written as twosome)
'knocking swine about in book' is the wordplay.
'knocking' says the letters should be written in reverse.
'swine' becomes 'sow' (sow is a kind of swine).
'about' indicates putting letters inside.
'in book' becomes 'tome' (a tome is a book. I am not sure about the 'in' bit.).
'sow' reversed gives 'wos'.
'wos' put into 'tome' is 'TWOSOME'.
Can you help me to learn more?
(Other definitions for twosome that I've seen before include "Pair, duo" , "game of golf" , "match" , "Item" , "Couple" .)