A stupid person; a person who does or says something stupid. 
The word is based on a common expression (in US English?) "duh!" According to Webster's Collegiate Dictionary, duh is an interjection used since 1974.
- used to express actual or feigned ignorance or stupidity
- used derisively to indicate that something just stated is all too obvious or self-evident
- In the last newsletter I asked what we should call people who are not in the DNRC. The rules were that the name should sound harmless to them but we would recognize it as a clever insult. I didn't specify that the name had to be sophomoric, but most of you accurately surmised that I would rate those suggestions higher. Hundreds of suggestions poured in.
- And the winner is:
- In-duh-viduals ***
- As promised, sainthood has been bestowed on the winner, Saint Heather of Beantown.
- Usage: "You're quite an In-duh-vidual, Andy."
- Meaning: "Someday you will be cleaning the gunk behind my refrigerator, houseboy."
- Although "In-duh-viduals" is the preferred name, any of the honorable mention names can also be used (see below). After all, it's not as though the In-duh-viduals will catch on.
A detailed treatment of the word, including commentary on its impact in common usage, is at http://www.logophilia.com/WordSpy/induhvidual.html.