Hormone has Linda near disaster (9)
I believe the answer is:
adrenalin
'hormone' is the definition.
(adrenalin is a kind of hormone)
'linda near disaster' is the wordplay.
'disaster' is an anagram indicator.
'linda'+'near'='lindanear'
'lindanear' anagrammed gives 'ADRENALIN'.
'has' acts as a link.
(Other definitions for adrenalin that I've seen before include "that pumps you up" , "Hormone that stimulates the nervous system" , "stimulant" , "A secretion" , "Stimulating hormone" .)