In many languages, the colors described in English as "blue" and "green" are colexified, i.e. expressed using a single cover term. To describe this English lexical gap, linguists use the portmanteau word grue, from green and blue, a term coined by the philosopher Nelson Goodman—with a rather different meaning—in his 1955 Fact, Fiction, and Forecast to illustrate his "new riddle of induction". The exact definition of "blue" and "green" may be complicated by the speakers not primarily distinguishing the hue, but using terms that describe other color components such as saturation and luminosity, or other properties of the object being described. For example, "blue" and "green" might be distinguished, but a single term might be used for both if the color is dark. Furthermore, green might be associated with yellow, and blue with either black or gray. According to Brent Berlin and Paul Kay's 1969 study Basic Color Terms: Their Universality and Evolution, distinct terms for brown, purple, pink, orange, and gray will not emerge in a language until the language has made a distinction between green and blue. In their account of the development of color terms the first terms to emerge are those for white/black (or light/dark), red and green/yellow. Afro-Asiatic Amazigh The word for blue in the Amazigh language is azerwal. In some dialects of Amazigh, like Shilha or Kabyle, the word azegzaw is used for both green and blue. Arabic The color of the sky is sometimes referred to as "the green" in Classical Arabic poetry, in which it is al-khaḍrā&apos; (). In Arabic the word for blue is generally azraq (). The Arabic word for green is akhḍar (). In Moroccan Arabic, the word for light blue is šíbi, whereas zraq () stands for blue and khḍar () for green. The word zrag () is used to describe the color of a suffocated person, and is also used pejoratively as a synonym to "dumb, stupid". Egyptian The ancient Egyptian word wadjet covered the range of blue, blue-green, and green. On the one hand, it was the name of a goddess, the patroness of Lower Egypt, represented as a cobra called Wadjet, "the green one", or as the Eye of Horus, also called by the same name. On the other hand, wedjet was the word used for Egyptian blue in faience ceramics. Hebrew In Hebrew, the word "" (pronounced ) means blue, while "" (pronounced )