A guide who leads others on a tour WordNet 3.0 & Open English WordNet

A tour guide or a tourist guide is a person who provides assistance, and information on cultural, historical and contemporary heritage to people on organized sightseeing and individual clients at educational establishments, religious and historical sites such as; museums, and at various venues of tourist attraction resorts. Wikipedia

Person who provides information and heritage interpretation to tourists Wikidata

A person who provides assistance and information to people on organised tours. Wiktionary

Guide on organised tours. Wiktionary (translation)