The most common and most likely answer to this crossword clue is the 8 letter word CONCEALS
I've seen this crossword clue in The Times
C
O
N
C
E
A
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S
More clues leading to the result CONCEALS
Buddy explains!

The straight part
We know that "Disguises" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case disguises = conceals.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 CONCEALS mean?
CONCEALS verb- To hide something from view or from public knowledge, to try to keep something secret.