There are various synonyms for the term "be lengthy." Some possible options include "be long-winded," "drag on," "run on," "be prolonged," or "take up a lot of time." All of these terms convey a similar idea: that something is taking longer than expected or than is necessary. Depending on the context, one of these synonyms might be more appropriate than others. For example, "be long-winded" might be a good choice for describing a speaker who is rambling on and on, while "be prolonged" could describe a situation that is taking longer than usual to resolve. Overall, these synonyms offer a way to communicate the concept of excessive length or duration.