masterling

Example:He is an expert in botany and has authored numerous books on the subject.

Definition:A person who has a thorough knowledge or skill in a particular area.

Example:She looked up to him as her guru in the field of martial arts.

Definition:A respected teacher or spiritual leader, often regarded as having a special power or knowledge.

Example:The authority on ancient history lives in Rome.

Definition:A person who is recognized as having an expert knowledge or skill in a particular field.