Retard is when someone kills you with a paperclip!
Like WOW bogdan sure is a retard
"Retard" is a slur that was used from the 1400's to the 1900's as a genuine slur to discriminate against those with mental health issues such as autism or ADHD. In the 2000's its meaning has shifted to be synonymous with stupid and is no longer targeted towards those with mental health issues. Many people on the internet will call you an asshole for it, some will support you for it, use at your own risk.
TLDR; Originally a slur, now synonymous for stupid.
Person 1: That guy is stupid.
Person 2: Yeah he's retarded.
Someone who looks up "retard" in the Urban Dictionary, only to find that they should know what a retard is, and they don't.
Don't know what a retard is? Then you are one. Simple.
A person who looks up retard in the dictionary not knowing what it is.
If you look up something you are MEANT to know, and don't know it, you are a retard
a person with a mental/physical disability. usually used as a vulgar word for people with autism or ADHD
Hannah: hey shes a retard! she cant even read *laugh*