The word is obnubilate. Pronounced \ob-NOO-buh-leyt\. This is a verb. It is defined as
To cloud over, or obscure.
Used in a sentence: In each of our lives, we are constantly bombarded with different levels of distractions that are designed by the Enemy to obnubilate our faith in God, which if not counteracted by prayer, can lead to doubt and confusion.
(1st Thessalonians ch.5: v.16-24)