Definition of "horror"

Their swarthy Hosts wou'd darken all our Plains, / Doubling the native Horror of the War, / And making Death more grim.

1712, Joseph Addison, Cato: A tragedy, published 1750, page 44

The Home Magazine for July (Binghamton and New York) contains ‘The Patriots' War Chant,’ a poem by Douglas Malloch; ‘The Story of the War,’ by Theodore Waters; ‘A Horseman in the Sky,’ by Ambrose Bierce, with a portrait of Mr. Bierce, whose tales of horror are horrible of themselves, not as war is horrible; ‘A Yankee Hero,’ by W. L. Calver; ‘The Warfare of the Future,’ by Louis Seemuller; ‘Florence Nightingale,’ by Susan E. Dickenson, with two rare portraits, etc.

1898 July 3, Philadelphia Inquirer, page 22

Could there be stories with more horror than these?

2009, Devin Watson, Horror Screenwriting‎

“Mrs. Yule's chagrin and horror at what she called her son's base ingratitude knew no bounds ; at first it was even thought that she would never get over it. […] ”

1905, Baroness Emmuska Orczy, chapter 1, in The Tragedy in Dartmoor Terrace‎

Those who enjoy horror, stories overflowing with blood and black mystery, will be grateful to Richard Marsh for writing ‘The Beetle.’

1917 February 11, New York Times, Book reviews, page 52

A well-received Johnny Fuller R & B horror called "Haunted House."

1990, Wayne Jancik, The Billboard Book of One-Hit Wonders, page 156

[…] there were hastily produced B movies, such as the peplums, the spaghetti westerns, the detective stories, the horrors.

2006, Pierluigi on Cinema

`My belief is that he had the horrors without knowin' it.'

1930, Norman Lindsay, Redheap, Sydney, N.S.W.: Ure Smith, published 1965, page 53