blackout

Where it comes from

The noun blackout grew from the English phrasal verb black out, meaning obscure or obliterate. It is recorded in early twentieth-century theater for extinguishing stage lights, while the verb had earlier described covering names or writing so they could not be read.

How the meaning developed

The staged darkness supplied a name that spread to failures of electric light, wartime concealment, and temporary losses of vision, consciousness, or memory. Other uses, including news and broadcast blackouts, generalize the same idea of suppression or interruption.