The most common and most likely answer to this crossword clue is the 12 letter word BLOODSTAINED
I've seen this crossword clue in The Times
B
L
O
O
D
S
T
A
I
N
E
D
More clues leading to the result BLOODSTAINED
Buddy explains!
The straight part
We know that "with Gore on its cover?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case with gore on its cover? = bloodstained.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does BLOODSTAINED mean?
BLOODSTAINED adjective- Stained, spotted or otherwise discolored with blood.
- Having the color of something which has been stained with blood.
- Responsible for the deaths of others; guilty of murder.
- (by extension) Guilty of wrongdoing.