The term "second in command" refers to the second highest ranking person in an organization or company. Synonyms for this term include "vice president", "deputy", "assistant", "lieutenant", "associate", "executive officer", and "adjutant". Depending on the context, some other possible synonyms could include "assistant manager", "chief operating officer", "deputy director", "senior manager", or "vice chairperson". Each of these synonyms suggests a slightly different level of authority and responsibility, so it's important to choose the most appropriate term for the specific situation. Regardless of the synonym used, the second in command plays a critical role in ensuring the success and continuity of the organization.