Blue–green distinction in language

In many languages, the colors described in English as "blue" and "green" are colexified, i.e., expressed using a single umbrella term. To render this ambiguous notion in English, linguists use the blend word grue, from green and blue, a term coined by the philosopher Nelson Goodman—with an unrelated 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.

The word for blue in the Amazigh (Berber) language is azerwal. In some dialects of Amazigh, like Shilha or Kabyle, the word azegzaw is used for both green and blue. It is likely cognate with the English word azure, which represents the colour between blue and cyan.^{[citation needed]}

The color of the sky is sometimes referred to as "the green" in some dialects of Classical Arabic poetry, in which it is al-khaḍrā' (الخضراء). In Arabic the word for blue is azraq (أزرق). The Arabic word for green is akhḍar (أخضر).

In Moroccan Arabic, the word for light blue is šíbi, whereas zraq (زرق) stands for blue and khḍar (خضر) for green. The word zrag (زرڭ) is used to describe the color of a suffocated person, and is also used pejoratively as a synonym to "dumb, stupid".^{[citation needed]}

The ancient Egyptian word wadjet covered the range of blue, blue-green, and green. 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. At the same time, wedjet was the word used for Egyptian blue in faience ceramics.

In Hebrew, the word כחול (pronounced [kaˈχol]) means blue, while ירוק ([jaˈʁok]) means green and has the same root, י־ר־ק (j-r-q), as the word for "vegetables" (ירקות, [jeʁaˈkot]). However, in classical Hebrew, ירוק can mean both green and yellow, giving rise to such expressions as ירוק כרישה 'leek green' (Tiberian Hebrew [jɔːˈroːq kəriː'ʃɔː]) to specify green to the exclusion of yellow. Like Russian and Italian, Hebrew has a separate name for light blue (תכלת, tekhelet)—the color of the sky and of tzitzit on the tallit, a ritual garment. This color has special symbolic significance in both Judaism and Jewish culture.