Acts of a dunderhead scattering seed (5)
I believe the answer is:
deeds
'acts' is the definition.
(deed is a kind of act)
'a dunderhead scattering seed' is the wordplay.
'a dunderhead' becomes 'd' (head letter of 'dunder').
'scattering' indicates an anagram.
'seed' anagrammed gives 'eeds'.
'd'+'eeds'='DEEDS'
'of' is the link.
(Other definitions for deeds that I've seen before include "Actions" , "Activities" , "Conveyancing documents" , "Feats" , "Exploits" .)