The most common and most likely answer to this crossword clue is the 8 letter word SCABBIER
S
C
A
B
B
I
E
R
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The straight part
We know that "get more marks" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case get more marks = scabbier.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 SCABBIER mean?
SCABBIER adjective- Affected with scabs; full of scabs.
- Diseased with the scab, or mange; mangy.
- Having a blotched, uneven appearance.
- Injured by the attachment of barnacles to the carapace of a shell.