If you were asked to explain what Cher, Prince, Bono, Adele, Washington, Voltaire, Plato, Jefferson, Franklin, Socrates, Confucius, Avicii, Homer, Sacagawea, and Sting all have in common it might take a few minutes to think about. But they are recognizable by a single name. You do not need their given and surname to know who the speaker is referring to when they speak. But what is this phenomenon known as?
A mononym is a name, and its meaning is to identify a person who is recognizable by a single proper noun. Usually this is the person’s given name and not their surname, but it could be either. Said another way, a person known by or addressed by a mononym is an mononymous (adjective form) person. Then there are famous couples, both of whom are recognizable by a single pair of proper nouns. Sonny and Cher, Lewis and Clark, and Desi and Lucy, just to name a few. These people are not always recognizable apart from their famous partner.
The use of mononyms is cultural in some cases, but in American and Europe it seems to go along with political, sports, or entertainment fame. It appears that a “star” knows they have arrived when people recognize them by just one name.
If you were in London and someone said: “Let me orientate you toward your destination.” it would not be incorrect use of the word. But in America the word would be orient (no “ate” on the end). The word can also mean to teach people how to recognize where East is as a necessity for orienteering. Locating East is very important for people in the armed forces.
Orientate is and is not a word in common use depending on which side of the pond you reside. However, it would be correct to say that Lewis and Clark would not have been able to orientate themselves correctly without the help of Sacagawea.