Book about female climbing pair (7)
I believe the answer is:
twosome
'pair' is the definition.
(synonyms)
'book about female climbing' is the wordplay.
'book' becomes 'tome' (a tome is a book).
'about' indicates putting letters inside.
'female climbing' becomes 'wos' (I can't explain this - if you can you should believe this answer much more).
'tome' enclosing 'wos' is 'TWOSOME'.
Can you help me to learn more?
(Other definitions for twosome that I've seen before include "game of golf" , "Item" , "match" , "Pair, duo" , "Couple" .)