Press cold youth resistant to change (8)
I believe the answer is:
ironclad
'resistant to change' is the definition.
I can't judge whether this definition defines the answer.
'press cold youth' is the wordplay.
'press' becomes 'iron' (ironing is a kind of pressing).
'cold' becomes 'c' (eg on taps).
'youth' becomes 'lad' (I've seen this before).
'iron'+'c'+'lad'='IRONCLAD'
Can you help me to learn more?
(Other definitions for ironclad that I've seen before include "Absolutely determined" , "Old armoured warship" , "Well armoured - perhaps an alibi?" , "19th-century warship" , "monitor, for example" .)