The term "blunder" is not inherently a bad word; it simply refers to a careless mistake or error. While it can carry a negative connotation, especially in serious contexts, it is often used in a neutral sense to describe an unintentional misstep. Whether it's considered offensive or inappropriate largely depends on the context in which it is used.
Blunder
Mistake, error, goof, blunder, miscalculation, misstep.
Take care to not repeat this blunder. I was very embarrassed with my blunder.
"gaffe" "social blunder"; embarassed; inept; awkward; social boor.
I want to see Maxwell Smart's next blunder.
Blunder can be a noun and a verb. Noun: An embarrassing mistake. Verb: To make an embarrassing mistake.
The worker's blunder nearly drove his employers to bankruptcy.
A bad move in chess is called a "blunder".
blunder
It seems as though Great Britain's attempt to imperialize the world was a blunder.
a social blunder
a stupid or careless mistake