What is Hairmet?
1.
A helmet (like a bicycle helmet) that has an increased height in order preserve the hairdoo of the wearer.
"Actually its not a helmet, its a hairmet. It's got extra room built in so you don't mess up your hairdoo."
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2.
A helmet with extra room built in so as to not mess up ones hair do.
I always wear my hairmet when i go cycling, keeps me safe and my hair looking good.
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3.
A self grown helmet comprised of ones own flaxen of hair;hairmets can vary from traditional "bowl cuts" to more sharpen, symmetrical varities as worn by Jim Carey in the picture "Dum and Dumber"
Damn, timmy just got stabbed in the head with a pitchfork! Good thing, his blonde hairmet protected him, orelse he would probably be dead!