oil

[12] Around the Mediterranean in ancient times the only sort of oil encountered was that produced by pressing olives, and so ‘oil’ was named after the olive. The Greek word for ‘olive’ was elaíā, and from it was derived elaíon ‘olive oil’. This passed into Latin as oleum, and reached English via Old French oile. By now it had begun to be applied to similar substances pressed from nuts, seeds, etc, but its specific modern use for the mineral oil ‘petroleum’ is a much more recent, essentially 19th-century development. => OLIVE OKOK [19] Few English expressions have had so many weird and wonderful explanations offered for their origin as OK. There is still some doubt about it, but the theory now most widely accepted is that the letters stand for oll korrect, a facetious early 19th-century American phonetic spelling of all correct; and that this was reinforced by the fact that they were also coincidentally the initial letters of Old Kinderhook, the nickname of US president Martin Van Buren (who was born in Kinderhook, in New York State), which were used as a slogan in the presidential election of 1840 (a year after the first record of OK in print).