Is deceptive, albeit not actively? (4)

I believe the answer is:

lies

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'is' is the definition.
The definition and answer can be both to do with fundamental existence as well as being verbs in their -s form.
Maybe they are linked in a way I don't understand?

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for lies that I've seen before include "Perversions of the truth" , "golfing situations" , "Falsehoods and prevarications" , "Tall stories" , "Terminological inexactitudes" .)

I've seen this clue in the Evening Standard.

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