Regurgitating Garth's lie is more horrible (9)

I believe the answer is:

ghastlier

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'regurgitating garth's lie is more horrible' is the definition.
I can't tell whether this defines the answer.

'garth's lie is more horrible' is the wordplay.
'is more' is a charade indicator (letters next to each other) (some letters added to the previous ones).
'horrible' indicates an anagram.
'garths'+'lie'='garthslie'
'garthslie' with letters rearranged gives 'GHASTLIER'.

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(Other definitions for ghastlier that I've seen before include "More pale" , "more repellent" .)

I've seen this clue in the Sydney Morning Herald.

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