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N).a very rare disease that was spread in the mid 1800's which is a mixture of autism and down syndrome but was later cured; although it has come back from the source downteccia aka D. Laveieri.

N).Some one that is really dumb.

alternate uses Downtistic
Dude daneille has a major case of downtism and needs to be institutionalized immediatly
by squigz April 25, 2008
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2
somebody so stupid that you are convinced they have Down syndrome and Autism.
"I'm convinced that who ever shot Harambe has Downtism."
by Goat Wizard June 17, 2017
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