Being busy is a common experience for people in today's fast-paced world. But using the same term repeatedly can get monotonous. Here are some synonyms to substitute "be busy" - occupied, engrossed, swamped, immersed, preoccupied, productive, bustling, active, frenzied, overworked. Depending on the context, other options could be buzzing, grinding, hustling, toiling, or slogging. For instance, "I am swamped with work right now" or "I'm completely immersed in this project." These words add texture and nuance to the language we use to describe ourselves and our workload, which can make our communication more enjoyable and compelling.