I sang a lot, drunkenly longing for home (9)
I believe the answer is:
nostalgia
'longing for home' is the definition.
(I've seen this before)
'i sang a lot drunkenly' is the wordplay.
'drunkenly' is an anagram indicator.
'i'+'sang'+'a'+'lot'='isangalot'
'isangalot' with letters rearranged gives 'NOSTALGIA'.
(Other definitions for nostalgia that I've seen before include "Sentimental reminiscing of analogist" , "Sentimental longing for the past" , "Yearning for past - homesickness" , "dreaming of the past" , "Longing for something past - isn't a goal (anag)" .)