It can mean anything or nothing (5)

I believe the answer is:

ought

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'nothing' is the definition.
(I've seen this before)

I cannot understand how the rest of the clue works.

(Other definitions for ought that I've seen before include "Have/has a duty (to do)" , "Has a duty (to do something)" , "Verb implying duty; zero, nothing (archaic)" , "Anything at all (archaic)" , "outdated anything at all?" .)

I've seen this clue in the Evening Standard.

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