She has them shortened to a degree (4)
I believe the answer is:
emma
'a degree' is the definition.
Both the answer and definition are singular nouns.
Maybe you can see an association between them that I can't see?
'she has them shortened' is the wordplay.
'she' becomes 'ema' ().
'has' is an insertion indicator.
'them' becomes 'em' (abbreviation).
'shortened' means to remove the first letter.
'em' with its initial letter taken away is 'm'.
'ema' enclosing 'm' is 'EMMA'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for emma that I've seen before include "Jane Austen heroine" , "It's a girl - ask me ma" , "Name of Nelson's Lady Hamilton" , "heroine of novel" , "Girl's name - Jane Austen novel" .)