Reebok was named by a man running a finger down a dictionary page.
The company started in November 1958 as Mercury Sports Footwear, set up by two brothers, Joe and Jeff Foster, in Bury. They came from a family of shoemakers. Apparel Search says they were grandsons of the founder of J.W. Foster and Sons, and left in 1958 to start a rival company.
Mercury was their first choice of name, but it caused trouble. A history site run by Joe Foster says that after about 18 months an accountant advised him to register the company name. A profile of Joe Foster in The Week says Mercury was already in use by Lotus and Delta, a division of the British Shoe Corporation. The Fosters were told to find something distinctive.
Joe Foster had a prize he had kept since childhood: a Webster's dictionary he had won in a race as a boy. He later described flipping through it and letting his finger land on random words. The Week says he rejected entries such as Mamushi, Mamzer and Redwood. Then he reached "reebok," which that account says the dictionary defined as "a light coloured antelope." Another account quotes the definition as "small South African gazelle."
The name fit. It was short, easy to say and available to register, and it suggested something light, quick and nimble, which suited a running-shoe maker. The company became Reebok in 1960.
The spelling is the older Dutch one. Dutch reebok meant a male roe deer, from ree (roe) and bok (buck), and South African Dutch used the word for a small antelope. The Dictionary of South African English records it in English from 1776, with spellings including rebok, reebok and rhebok. Modern Afrikaans uses ribbok.
Which dictionary Foster used is unclear. Apparel Search says it was a South African edition, but a podcast account calls it an American Webster's, so we cannot settle that. Wikipedia says the name is Afrikaans for the grey rhebok but flags that claim as disputed. The sources otherwise call the animal an antelope or a gazelle.
The older firm, J.W. Foster and Sons, was absorbed into Reebok in 1976, according to a footnote in Wikipedia. The antelope name has outlasted the family firm by decades.