Get flat denial, occasionally backtracking (3)

I believe the answer is:

lie

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'get flat' is the definition.
I can't tell whether this defines the answer.

'denial occasionally backtracking' is the wordplay.
'occasionally' indicates alternate letters.
'backtracking' is a reversal indicator.
The alternating letters of 'denial' are 'eil'.
'eil' back-to-front is 'LIE'.

Can you help me to learn more?

(Other definitions for lie that I've seen before include "Fib - be prone" , "Perversion of the truth" , "Be prone - misrepresent the facts" , "Pork pie" , "situation" .)

I've seen this clue in The Independent.

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