Stupid new hanger-on missing opening (6)

I believe the answer is:

noodle

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'stupid' is the definition.
(both can mean a stupid person)

I don't understand how the remainder of the clue works.

(Other definitions for noodle that I've seen before include "Idiot" , "Staple of Chinese cuisine" , "Slangy head or pasta strip" , "Foolish person or slangy head" , "In slang, a foolish person or just the head" .)

I've seen this clue in The Independent.

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