First of inebriates getting dry in party — “same again” (5)
I believe the answer is:
ditto
'same again' is the definition.
(I've seen this before)
'first of inebriates getting dry in party' is the wordplay.
'first of' says to take the initial letters.
'getting' means one lot of letters go next to another.
'dry' becomes 'tt' (abbreviation for teetotal).
'in' is an insertion indicator.
'party' becomes 'do' (do is a kind of party).
The initial letter of 'inebriates' is 'i'.
'i'+'tt'='itt'
'itt' placed within 'do' is 'DITTO'.
(Other definitions for ditto that I've seen before include "Do alternative" , "Repeat the word(s) above" , "couple of marks" , "Two dots say same again" , "Same again, indicated by two dots" .)