1 definition by Matt N

1. The very means of slapping someone (or something) in the face (or elsewhere) with ones penis. derived from the sound it makes when contact is made.
1. WHOPACHA! (*screamed whilst performing the act.)

2. That bitch is gonna cop a whopacha in the face!

3. that n00b just got whopacha'd

4. OMGWTFBBQ! i just got whopacha'd
by Matt N May 6, 2006
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