Top definition
When you get a boner by looking at asses. Usually female asses.
Guy #1: Did you see ______ lastnight?

Guy #2: Yeah, man. _______ gives me an errectum.

Guy #1: An errectum? What's that?

Guy #2: You know? An errectum. Where you get a boner by looking at a smoking hot ass.
by Beau Vyne March 29, 2010
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