1.is used refer to any member of a large family of catfish native to Central and South America that posess sucker shaped mouths that are often introduced to aquariums to eat algae.

2. used to refer to a very low, scummy individual, a "bottom feeder".
1.I had a pleco in my 10G tank, but he outgrew it.

2. that guy is a total pleco, he asked my married sister to do it with him.
by fishcatch22 March 2, 2007
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a bottom feeder.

one who attaches themselves to other peoples environment as to be a part of it, or "in the know".
This was a pretty hot spot until this pleco started coming around.
by CT January 29, 2004
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noun, verb.

a dictionary app for people learning Chinese.
- I don't know what does that character mean.
- Pleco it!
by syytetty July 6, 2020
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Fish that eats scum from the bottom of the tank
by Victoria March 22, 2004
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