Most thoroughly is a phrase used to describe a complete and comprehensive evaluation or examination of something. There are many synonyms that can be used to replace this phrase, such as completely, exhaustively, comprehensively, meticulously, rigorously, wholly, entirely, precisely, painstakingly, and thoroughly. Each of these synonyms carries a slightly different connotation, but they all suggest a deep and comprehensive approach to understanding or analyzing something. When looking for alternatives to most thoroughly, it's important to consider the context in which the phrase is being used and choose a synonymous term that accurately conveys the intended meaning. Ultimately, the choice of synonyms depends on the context of the sentence and the writer's intended meaning.