Someone who is usually fairly intelligent but does something moronic or out of character would be a ploon.
Ryan thought the time was 3am because the clock stopped working even though it was still sunny, what a ploon.
by Mancazza March 18, 2011
The disctinctive purple vagina of a black female. Derived from the purple colour of a plum and the word poon.
I entered an ebony porn site looking for poon, but I only found ploon.
by Fernando Leon September 24, 2008
by Peter Santafe January 08, 2005