Load of fun, dammit! (5)
I believe the answer is:
blast
This clue is a triple definition!
'load' is the first definition.
(thesaurus)
'of' is a link.
'fun' is the second definition.
'dammit' is the third definition.
(both are mild expletives)
(Other definitions for blast that I've seen before include "Loud noise from a horn" , "Blow up or swear" , "Severely criticise" , "Damn - explosion" , "Strong gust of air" .)