Security has no pass for side (7)

I believe the answer is:

lateral

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'side' is the definition.
(synonyms)

I cannot understand how the remainder of the clue works.

(Other definitions for lateral that I've seen before include "Situated at or extending to the side" , "This kind of thinking is unconventional" , "Sort of thinking" , "Tall ear (anag.)" , "Side branch" .)

I've seen this clue in The Telegraph.

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