► basicforming the main or most necessary part of something: There are two basic problems here. In this course, students will learn the basic principles of chemistry.
► fundamental relating to the most basic and important parts of something: The fundamental problem is a lack of resources.
► essential the essential parts, qualities, or features of something are the ones that are most important, typical, or easily noticed: Religion is an essential part of their lives.
► central more important than anything else: The central theme of the novel is the horror of war.
► underlying relating to the main reason for something happening or existing, when this is not easy to discover: Doctors are still trying to find the underlying cause of her illness.
► inherent formal a quality that is inherent in something is a natural part of it, and cannot be separated from it: There are inherent risks in starting your own business.
► intrinsic formal relating to the basic nature or character of something: Humor is an intrinsic part of his personality.