At a loose end only briefly in the North just after the birth (8)
I believe the answer is:
neonatal
'north just after the birth' is the definition.
I can't judge whether this defines the answer.
'at a loose end only briefly in' is the wordplay.
'loose end' becomes 'ne' (I can't justify this - if you can you should give a lot more credence to this answer).
'briefly' means to remove the last letter.
'in' indicates putting letters inside.
'only' with its final letter removed is 'onl'.
'ne'+'onl'='neonl'
'at'+'a'='ata'
'ata' placed into 'neonl' is 'NEONATAL'.
'the' is the link.
Can you help me to learn more?
(Other definitions for neonatal that I've seen before include "Of a new-born infant" , "Of or for the newly born" , "relating to babies" , "at a very young age" , "Like clinic" .)