When we talk about something happening "back-to-back", it means that events are placed one after another or without any break. This term can be replaced by other synonyms, such as "consecutive", "constant", or "non-stop". Additionally, words like "sequential" or "successive" convey the same idea. Other synonyms for "back-to-back" include "continuous", "uninterrupted", and "recurring". If you want to emphasize the pace of an activity, you can use "rapid-fire" or "backbreaking". So, when your schedule is jam-packed with a lot of events happening one after the other, you can use one of the many synonyms for "back-to-back" to convey your message more effectively.