To give a little devil beer is a fatal thing to do (6)
I believe the answer is:
impale
'a fatal thing to do' is the definition.
I can't judge whether this defines the answer.
'to give a little devil beer' is the wordplay.
'to give' says to put letters next to each other.
'a little devil' becomes 'imp' (an imp is a little demon).
'beer' becomes 'ale' (type of beer).
'imp' put next to 'ale' is 'IMPALE'.
'is' acts as a link.
Can you help me to learn more?
(Other definitions for impale that I've seen before include "Transfix, pierce (with a sharp instrument)" , "shut in as before" , "Fix as on a sharp stick" , "Puncture" , "Kill by piercing with a spear or sharp pole" .)