look up any word, like ratchet:
 
1.
Mr. Krabs' business rival on Spongebob Squarepants. He owns a shitbox restaurant called the Chum Bucket, where he makes secret evil plans to steal the Krabby Patty formula and therefore attract business. He always fails.
Plankton

"You'll never catch me, Mr. Krabs. I went to college!"
by Some idiot who thinks you are gay, September 02, 2006
 
3.
a small creature that bugs the hell outta you when you don't need his/her bullshit at the moment
SpongebobSquarepants
You bitch, you-you plankton-you just stole my formula of how to make fried chicken
by bigblack&hairy235 February 25, 2009
 
4.
Word used to describe utterly detestable and braindead peasant underclass. These are the slutty, often chav bitches at parties who you wish to kill slowly. However, despite appearances, there is a reason for their existence. Their sluttish antics (such as false lesbianism) distract the male equivalent of plankon, thus reducing 'competition' for the more discerning male.

Plankton are simultaneously a disease and a cure.
"This place is full of plankton"

"Yeah, lets go"
by Figure Number Five June 30, 2005
 
5.
Person of little or no brains, an imbecile.
What a complete Plankton
by Technofrog March 22, 2003
 
6.
A person who bums everything and anything off of people. Also can be said instead of word bum.
hey can i plankton you ?

Dan Hegarty then gave me a stog.
by Mike Chi December 14, 2008
 
7.
someone who while claiming to play does not actually participate in extreme frizbee or other games but instead just stands there and only catches it if it goes for them
"dude hugh was such a plankton yesterday during frizbee"

"conor quit being a planton and go for it!"
by Althalus June 03, 2007