This is the 8440th most frequent Dutch word.
gruwel
Horror; atrocity; something horrifying or disgusting.
Here, 'gruwel' is used as a noun to denote the intense horror or terror associated with war.
De gruwel van oorlog zorgt voor veel pijn en verdriet.
The horror of war causes much pain and sorrow.
In this sentence, 'gruwel' again takes the form of a noun to express a strong aversion or fear towards spiders.
Ze vindt de gruwel van spinnen ondraaglijk.
She finds the horror of spiders unbearable.
Here, 'gruwelijke' is the adjective form of 'gruwel', used to describe the nature of the story as shocking and horrifying.