IPA: /tɛnəˈbrɪfɪk/
KK: /tɛnəˈbrɪfɪk/
Relating to or causing darkness or gloom.
The tenebrific atmosphere of the old castle made everyone feel uneasy.
Tenebrific → It is formed from "tenebrae" (meaning darkness) and "-fic" (meaning making or causing). The word "tenebrific" means causing or producing darkness.
Think of 'darkness' ('tenebrae') being 'made' or 'caused' ('-fic') — that's why tenebrific refers to something that creates darkness.
No commonly confused words.