There are several synonyms for the term "key group" which can be used in various contexts. Some of the common synonyms include "core group", "crucial group", "central group", "primary group", "essential group", and "vital group". These synonyms refer to a group of individuals or entities that play a paramount role in achieving a particular objective. They are usually the core team or decision-makers who possess the expertise, skills, knowledge, and experience necessary for successful completion of a project or task. These synonyms can be used interchangeably depending on the context and tone of the language used.