The phrase "first degree" refers to the highest level or closest relationship to a particular person or thing. Some synonyms for "first degree" include primary, premier, topmost, foremost, and highest. Other words that can be used interchangeably with "first degree" include initial, original, and foundational. In the legal sense, "first degree" commonly refers to the most severe level of a crime, such as first-degree murder or first-degree assault. In this context, words like intentional, premeditated, and planned can be used as synonyms for "first degree." Understanding the various synonyms for "first degree" can help enhance one's communication skills and add precision to their language usage.