Hiss the slackers who won't make a straightforward move (5)

I believe the answer is:

sidle

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'move' is the definition.
(I know that sidle is a type of move)

I don't understand the rest of the clue.

(Other definitions for sidle that I've seen before include "Walk furtively sideways" , "sidewalk" , "Walk sideways in furtive manner" , "Edge along furtively" , "Make cautious progress" .)

I've seen this clue in the Evening Standard.

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