Is a person who provides assistance or tutelage to one or more people on certain subject areas or skills. He or she spends a few hours on a daily, weekly, or monthly basis to transfer their expertise on the topic or skill to the student.

 Is someone who engages in any activity that makes a social process easy or easier. He or she often helps a group of people to understand their common objectives and assists them to plan how to achieve these objectives; in doing so, he/she remains "neutral", meaning he/she does not take a particular position in the discussion.

A person who supports a learner or client in achieving a specific personal or professional goal by providing training and guidance. 

A person who promotes interest in or enthusiasm for something, shares his or her words of help with others. Anyone who stimulates others to take action or to pursue and realize a dream, vision or aspiration.

 Someone who teaches people particular skills, especially the skills they need to do a job.

An experienced and trusted adviser. Is a person who trains and guides someone, like the second-grade English teacher who saw the spark of creativity in your writing and encouraged you to become a professional author.

Defines the interface for communication between Colleague objects. He/she implements the interface and coordinates communication between Colleague objects. It is aware of all of the Colleagues and their purposes with regards to inter-communication. A person who attempts to make people involved in a conflict come to an agreement; a go-between.

Is a person whose role is to act as a neutral participant in a group, debate or discussion, holds participants to time limits and tries to keep them from straying off the topic of the questions being raised in. A chairman of a group.