Occasionally meaning 'one who blights
'. But blighting
is not a common activity in today's society, and the blight
is seen more as a natural force than an activity of us humans.
Nowadays blighter is an informal tag, often used to show lack of respect for the person thus referred to. It usually refers to a male.
Can be used as a synonym either for fellow or fool.
Much more common in the UK than in America.