Another euphemism was that class for less-smart kids were called "special education", and so the kids were called "special". You could use "silly" or "cute" in some contexts. But in general, I'd avoid looking for any word that means anything remotely like "stupid" if you're trying to keep a conversation friendly. More @Wikipedia
Get the latest news about Special Education from the top news sites, aggregators and blogs. Also included are videos, photos, and websites related to Special Education.
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.