Fool! Work in Daintree ends! (4)
I believe the answer is:
dope
'fool' is the definition.
(both can mean a stupid person)
'work in daintree ends' is the wordplay.
'work' becomes 'op' (common abbreviation for 'opus').
'in' is an insertion indicator.
'ends' says to hollow out the word (remove centre letters).
'daintree' with its middle taken out is 'de'.
'op' going within 'de' is 'DOPE'.
(Other definitions for dope that I've seen before include "Fool - cannabis" , "Information, fool" , "Information; nitwit" , "Charlie" , "Aircraft fabric varnish" .)