Grim morgues out East (8)
I believe the answer is:
gruesome
'grim' is the definition.
(I know that grim can be written as gruesome)
'morgues out east' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'east' becomes 'E' (synonyms).
'morgues' anagrammed gives 'gruesom'.
'gruesom'+'e'='GRUESOME'
(Other definitions for gruesome that I've seen before include "'Grisly, macabre (8)'" , "Sickening, macabre" , "Shockingly repellent; inspiring horror" , "Repulsive, horrific" , "Repulsive, horrid" .)