A collateral adjective is an adjective that is identified with a particular noun in meaning, but that is not derived from that noun. For example, the word bovine is considered the adjectival equivalent of the noun cow, but it is derived from a different word, which happens to be the Latin word for "cow". Similarly, lunar serves as an adjective to describe attributes of the Moon; moon comes from Old English mōna "moon" and lunar from Latin luna "moon". The adjective thermal and the noun heat have a similar semantic relationship. As in these examples, collateral adjectives in English very often derive from the Latin or Greek translations of the corresponding nouns. In some cases both the noun and the adjective are borrowed, but from different languages, such as the noun air (from French) and