1.NounA gig (temporary or informal job) being done on the side; a person's non-primary job or other occupation, often distinguished by factors such as formality, legality, personal priority, and/or financial return."I work in retail, but I also have a side gig as a content creator.; Sure, I do commercial and sponsored things, but those are just side gigs. Acting on the big screen will always be my passion.; That guy wants to appear as a serious and formal businessman and not talk about his side gig where he deals drugs on the street."