Airhead

Etymology 1
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Noun

 * 1)  A silly, foolish or unintelligent person.
 * 2)  An insufferable show off but doesn't really know what he's talking about.

Synonyms

 * bimbo, bubblehead, valley girl, dumb blonde, space cadet no brains.

Etymology 2
By analogy with beachhead, bridgehead, railhead.

Noun

 * 1) A landing area for aircraft for supplying an operation, military or other, usually temporary.
 * 2)  An area of hostile territory that has been seized by paratroopers or helicopter-based troops to ensure the further landing of troops and/or materiel.