Warn of drink leading to death (7)
I believe the answer is:
portend
'warn' is the definition.
(thesaurus)
'drink leading to death' is the wordplay.
'drink' becomes 'port' (port is a kind of drink**).
'leading to' is a charade indicator (letters next to each other) (some letters go before or lead others).
'death' becomes 'end' ('end' can be a synonym of 'death').
'port'+'end'='PORTEND'
'of' is the link.
(Other definitions for portend that I've seen before include "forecast" , "Foreshadow" , "Betoken; presage" , "Threaten" , "Give warning" .)