The word "Non-professional" indicates a person or an activity that is not related to a particular profession or is not done in a professional manner. Antonyms of the word "Non-professional" include "Professional," indicating a person who is skilled and trained in a particular field and follows professional ethics and practices. "Expert," on the other hand, means a person who has extensive knowledge and skills in a particular field. "Experienced," "Qualified," and "Competent" are some other antonyms of "Non-professional" that denote the skills, knowledge, and expertise of a person in a particular profession. These antonyms help describe a competent, trained, and skilled person that is proficient in their job.