What the devil is a cruet I hear you cry? Don't cry I say, here's a tissue. The word cruet comes from the Old French word crue, meaning 'earthen pot.' They have long been used to serve oil and vinegar at the table. I have one for my olive oil next the the stove (which I use all the time) and one for balsamic vinegar which aI use less often, for dressing salads and such. These make great gifts for anyone who loves to cook.