President a head of government had to harangue? (5)
I believe the answer is:
grant
'president' is the definition.
(I know that Grant is a president)
'a head of government had to harangue?' is the wordplay.
'a head of' indicates taking the first letters.
'had' means one lot of letters go next to another.
'to harangue?' becomes 'rant' (synonyms).
The first letter of 'government' is 'g'.
'g'+'rant'='GRANT'
(Other definitions for grant that I've seen before include "Give freely" , "Give (a right, property, etc)" , "Formally give (a right)" , "19th century president" , "Concede, like an American general" .)