Cut up nurses worried that it's life-threatening (5,4)
I believe the answer is:
death trap
'life-threatening' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'cut up nurses worried that' is the wordplay.
'cut' becomes 'pared' (I've seen this before).
'up' shows that the letters should be reversed in order (in down clue: letters go upwards).
'nurses' indicates putting letters inside (nurse can mean to hold onto or harbour).
'worried' is an anagram indicator (worry can mean to interfere with or disturb).
'pared' in reverse letter order is 'derap'.
'that' is an anagram of 'atht'.
'derap' going around 'atht' is 'DEATH-TRAP'.
'it's' acts as a link.
Can you help me to learn more?
(Another definition for death trap that I've seen is " Unsafe building, for instance".)