First nail hammered to restrain prophet (9)
I believe the answer is:
inaugural
'first' is the definition.
(synonyms)
'nail hammered to restrain prophet' is the wordplay.
'hammered' indicates an anagram (slang term for drunk).
'to restrain' is an insertion indicator.
'prophet' becomes 'augur' (augur is a kind of prophet).
'nail' is an anagram of 'inal'.
'inal' enclosing 'augur' is 'INAUGURAL'.
(Other definitions for inaugural that I've seen before include "Of a ceremony officially marking the beginning of something" , "It may be delivered" , "First address" , "President's address" , "Relating to start of job or course" .)