Regularly shifty, lie (3)

I believe the answer is:

sit

'lie' is the definition.

'regularly shifty' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
The alternating letters of 'shifty' are 'SIT'.

(Other definitions for sit that I've seen before include "Use a chair" , "Be seated" , "as magistrates do" , "Order dog to behave" , "Take weight off feet" .)

I've seen this clue in The Times.

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