This is a very slang term to say that you have an erection.
Proper use of this is when a hot girl comes up to you to ask what time it is and you reply with this.
I heard this on the show "Beevus and Butthead."
Hot girl: Do you know what time it is?
Guy with erection: It's High Noon on my sundial.
by Spartanboy3000 April 4, 2010
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