The most common and most likely answer to this crossword clue is the 9 letter word REPTILIAN
I've seen this crossword clue in The Times
R
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P
T
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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.
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What does REPTILIAN mean?
REPTILIAN noun- A reptilian animal: a reptile.
- A reptilian person, especially (racial slur) a Jew.
- A reptilian alien, especially (often capitalized) of a shapeshifting race purported to secretly control the world.
- Of or relating to the members of the class Reptilia.
- Reptilelike.
- Unthinking, low, base, contemptible.
- Cold-blooded, treacherous, unavoidably selfish and hostile.