Kodak is not a word in any language. It is not an acronym, a place or a person. George Eastman built it from nothing, on purpose, so that it could only ever mean his camera.
Eastman had been in the photography business since 1881, when he and Henry Strong founded the Eastman Dry Plate Company. In 1888 he trademarked a name he had invented for his new hand-held camera. Etymonline gives the same year.
He set himself rules. Wikipedia lists three: the name should be short and easy to pronounce. It should not resemble any other name or be associated with anything else. Rather than adapt an existing word, he made one up.
The letter came first. "It seems a strong, incisive sort of letter," Eastman said of K, in a quote reprinted by the University of Rochester. He tried many combinations of letters that started and ended with it. "The word 'Kodak' is the result," he said. Wikipedia adds that he worked it out with his mother, Maria, using an anagram set.
The company kept repeating the point. A 1920 Kodak advertisement, quoted on Wikipedia, said the name had simply been invented from letters of the alphabet to meet the company's trademark requirements. No hidden meaning was ever offered, because there was none to offer.
The company took the product's name, not the other way round. The firm became the Eastman Dry Plate and Film Company in 1884 and the Eastman Company in 1889. It was renamed Eastman Kodak on May 23, 1892.
The strategy worked well enough that the name slipped into ordinary grammar. Etymonline, which calls the name an "arbitrary coinage," says it was in use as a verb by 1891. Merriam-Webster still lists "kodak" as a verb, "to take photographs with a Kodak camera." It also keeps a trademark entry, defined as "used for a small hand camera."
That is the odd fate of a perfect brand name. Eastman wanted a word that pointed only to his product, and English speakers obliged by turning it into something you could do.