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1.
A condition that sadly exists in only a small percentage of the population and of that small percentage the majority are women.

The condition results in the individual having a dazzling smile that is present for the majority of the time.

In extreme cases the smileyitis becomes contagious and is naturally transferred to anyone the individual may come into contact with.
Tell me about your new friend Valerie?

She's awesome, smart, funny, easy to talk to, but the thing I like about her the most is that she has a contagious case of 'Smileyitis'.
by The Candian Brit November 03, 2011