Infernal barrier meets terrible end (6)
I believe the answer is:
damned
'infernal' is the definition.
(I know that infernal can be written as damned)
'barrier meets terrible end' is the wordplay.
'barrier' becomes 'dam' (dam is a kind of barrier).
'meets' is a charade indicator (letters next to each other).
'terrible' indicates an anagram.
'end' anagrammed gives 'ned'.
'dam'+'ned'='DAMNED'
(Other definitions for damned that I've seen before include "Cursed" , "Abominable" , "Those condemned to eternal punishment" , "Consigned to everlasting punishment" , "Consigned to hell or perdition" .)