Stimulant for a N. Ireland development (9)
I believe the answer is:
adrenalin
'stimulant' is the definition.
(I've seen this before)
'a n ireland development' is the wordplay.
'development' is an anagram indicator.
'n'+'ireland'='nireland'
'nireland' is an anagram of 'drenalin'.
'a'+'drenalin'='ADRENALIN'
'for' acts as a link.
(Other definitions for adrenalin that I've seen before include "that pumps you up" , "Hormone affecting metabolism" , "Hormone affecting circulation and breathing" , "A secretion" , "stimulant" .)