Used to describe something that cannot be defended.
Es indefendible que algunas personas sigan ignorando el cambio climático a pesar de las evidencias presentadas.
It is indefensible that some people continue to ignore climate change despite the evidence presented.
Su argumento era indefendible, y la audiencia no pudo evitar reírse.
His argument was indefensible, and the audience couldn't help but laugh.