"Day gig" refers to a regular job that a person holds while pursuing their passion or side hustle. Antonyms for this term could include "full-time career," "primary occupation," or "main source of income." These terms imply that a person's job is not just a temporary gig, but a long-term commitment and mainstay of their professional life. Other antonyms for "day gig" could include phrases like "passion project," "creative pursuit," or "side hustle," indicating that a person is prioritizing their artistic, creative, or entrepreneurial pursuits over a steady job. Ultimately, the opposite of a day gig depends on one's personal values and career goals.