What is "safety-valve"

Usage examples of "safety-valve".

But in some cultures it developed as a religious holiday peculiar to theocracies: the safety-valve holiday, the day of excesses, of sin without punishment, the saturnalia.

Hence the fanaticisms and intoxications--religious, political, and sexual, the Nazis, the Klan, Hell's Angels, the Circus Maximus, the dreary fascination of the TV screen, witch-burnings, Mickey Spillane and James Bond, pachinko parlors, alcoholic stupors, revivals, tabloid newspapers, and juvenile gangs--all of which, as things stand, are the necessary safety-valves and palliatives for human beings whose very existence is defined in self-contradictory and self-defeating terms.