it basically means that they are as boring as a dead person, as 'stiff' is slang for a dead body.
strong or potent to the taste or system, as a beverage ormedicine: He was cold and wanted a good stiff drink.
Dull, boring, plain, common.
that you are a boring person
boring
Calling someone "vanilla" can imply that they are plain, boring, unadventurous, or lack creativity or uniqueness. It often suggests a lack of excitement or originality in their behavior or personality.
When someone sucks the fun out of the party/place your at. And its no fun around them. They are boring.
No it can't call someone
No it can't call someone
stiff
"Cared stiff" is likely a misinterpretation or a typographical error of the phrase "cared for." In a more colloquial sense, "stiff" can refer to someone who is inflexible or unyielding in attitude. If you meant a different phrase or context, please provide more details for clarification.
meaning stiff
According to the urban dictionary it does mean boring.