We’ve had million of discussions on this topic. More than 160 synonyms nowadays! We are so creative .!
What about this definition:
A virtual human is a computer generated human simulation with artificial intelligence. A virtual human can have a CG human body, and CG voice and computer empowered senses.Virtual humans can be applied in various domains such as education, marketing, branding, training & sales.
A virtual agent is a virtual human acting on behalf of an organization, communicating with potentially millions of stakeholders
A brand agent is a virtual human acting of behalf of a brand, communicating with potentially millions of stakeholders
A virtual assistant is a virtual agent specialized in service.
A chatbot is a virtual human specialised in social chat on a wide variety of topics.