Articulate American beast that may make your hair stand on end (6)

I believe the answer is:

mousse

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But I can't explain it at all! Could you help me understand?

(Other definitions for mousse that I've seen before include "For us, some kind of dessert" , "Whipped cream dessert" , "Whipped cream and egg dish" , "Aerosol foam used in hair styling" , "Creamy dish" .)

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