oily I. \ˈȯilē, -li\adjective (-er/-est) Etymology:oil (I) + -y 1.: of, relating to, or consisting of oil : containing oil : having the nature or qualities of oil 2.: covered or impregnated with oil : greasy < rid of rubbish and oily rags — My Weekly Reader > 3.: unctuously ingratiating or insinuating : plausible, smooth, suave < an oily, sycophantic press agent — Lee Rogow > II. adverb : oilily < of oily smooth texture >