Hottentot

Borrowed from Dutch Hottentot, its first known use in Dutch being in the 1650s. The third edition of the Oxford English Dictionary concluded in 2008 that hottentot came into English in the seventeenth century. But it finds that no definitive etymology of Dutch hottentot can so far be given:

A very large number of different etymologies for the name have been suggested ... The most frequently repeated suggestion ... is that the word was a spec. use of a formally identical Dutch word meaning ‘stammerer, stutterer’, which came to be applied to the Khoekhoe and San people on account of the clicks characteristic of their languages. However, evidence for the earlier general use appears to be lacking. Another frequent suggestion is that the people were so named after one or more words which early European visitors to southern Africa heard in chants accompanying dances of the Khoekhoe or San ... but the alleged chant is rendered in different ways in different 17th-cent. sources, and some of the accounts may be based on hearsay rather than first-hand knowledge.

It does seem clear, however, that hottentot was an exonym, that is, not the Khoikhoi's own name for themselves but rather a foreign term applied to them.