The word "multistep" is usually used to describe a process that involves several stages or steps. However, there are several synonyms that can be used instead of "multistep" to indicate the same meaning. Some of the commonly used synonyms include "multi-stage," "complex," "complicated," "elaborate," "involved," "intricate," and "multi-phased." Each of these synonyms indicates that a process has several steps or stages that must be completed in a specific order. Using synonyms like these can help to add variation to your writing and make it more engaging and interesting for your readers.