(historical) A period in the United States between the 1940s and 1950s marked by a widespread fear of communism and socialism; McCarthyism.

Alternative form of scare the living daylights out of

(idiomatic) To scare something or someone to a great degree.

(transitive, informal) To frighten someone to such an extent that they behave irrationally.

(idiomatic) To scare something or someone to a large degree.

In a manner that scares; frighteningly.