The phrase "to become fearful" means to experience or develop a feeling of fear, anxiety, or apprehension.
Sentences with «to become fearful»
It can prevent your dog from becoming fearful of the unknown and from becoming aggressive as a result of being fearful. (pawsitivelyfabulous.com)
For example, many dogs become fearful when they meet new people. (straightpoop.com)
People become fearful when it becomes clear to them that the writing has been on the wall for some time that they might lose their job. (arichlife.passionsaving.com)