Generally speaking, it is better to be robust than it is to be frail, so yes, frail has a negative connotation. It means weak and fragile, easily damaged. Very old people tend to become frail.
A negative connotation for willowy could be frail or weak, suggesting a lack of strength or substance.
Perhaps frail and weak
It is a negative connotation.
uneasy is negative connotation
It is a negative
negative connotation for child
It is a negative connotation?
negative
negative
"Protruding" has a negative connotation; it connotes excess.
Positive connotation: Exciting Negative connotation: Risky
This is a negative connotation.