Yours truly is unfortunately up for meat (6)
I believe the answer is:
salami
'meat' is the definition.
(salami is a kind of meat)
'yours truly is unfortunately up' is the wordplay.
'yours truly is' becomes 'im'.
'unfortunately' becomes 'alas' (I've seen this before).
'up' says the letters should be written backwards (in down clue: letters go upwards).
'im'+'alas'='imalas'
'imalas' written backwards gives 'SALAMI'.
'for' is the link.
(Other definitions for salami that I've seen before include "Italian garlic sausage" , "Preserved meat sausage" , "Savoury snack" , "Garlic- flavoured sausage" , "Spiced Italian sausage" .)