Creosote from both oil shale and petroleum, and are known as oil-tar creosote when derived from oil tar, and as water-gas-tar creosote when derived from the tar of water gas. Creosote also has been made from pre-coal formations such as lignite, yielding lignite-tar creosote, and peat, yielding peat-tar creosote. The term creosote has a broad range of definitions depending on the origin of the coal tar oil and end use of the material. With respect to wood preservatives, the United States Environmental Protection Agency (EPA) considers the term creosote to mean a pesticide for use as a wood preservative meeting the
English words of Greek origin "bacterium" < βακτήριον 'stick (diminutive)' is a kind of microorganism rather than a small stick or staff. This also applies to combining forms used in neologisms: "-cyte" or "cyto-" < κύτος 'container' means biological cells, not arbitrary containers; "-oma" < -ωμα, a generic morpheme forming deverbal nouns such as "diploma" 'a folded thing' and "glaucoma" 'greyness', comes to have the very narrow meaning of 'tumor' or 'swelling', on the model of words like "carcinoma" < καρκίνωμα. For example, "melanoma" does not come from Greek μελάνωμα 'blackness', but rather from the modern combining forms "melano-" 'dark (in biology)' + "-oma" 'tumor'.