When a person has been threatened and made to feel timid, he becomes intimidated. You might be intimidated by a large barking dog, a mean boss, or a pair of skinny jeans you'd love to fit into.
The adjective intimidated is derived from the similarly spelled Latin intimidare, meaning “to frighten." Notice within both the English adjective and Latin root another adjective timid, “fearful.” That should help you remember the meaning. Maya Angelou said, “Education helps one cease being intimidated by strange situations.” When you are familiar with something, it becomes less frightful. Synonyms for intimidated include afraid and daunted.