Pronunciation: [sˈʌnfast] (IPA) 
The spelling of the word "sunfast" is straightforward when using the International Phonetic Alphabet (IPA). "Sunfast" is transcribed as /sʌn.fæst/ in the IPA. The first syllable "sun" is pronounced as "sʌn" with the "ʌ" sound similar to the "u" in "run." The second syllable "fast" is pronounced as "fæst" with the "æ" sound resembling the "a" in "cat." Together, the word means resistant to fading or damage from sunlight.
Sunfast is an adjective that is commonly used to describe a substance, particularly a dye or pigment, which possesses excellent resistance to fading or discoloration when exposed to sunlight or ultraviolet (UV) radiation. The term is derived from the combination of the words "sun" and "fast," with fast meaning "firmly fixed or held in place."
When applied to textiles or materials, sunfastness refers to how well the colors retain their original vibrancy and intensity when exposed to prolonged sunlight. Fabrics that are sunfast are less prone to fading, and their hues remain true for an extended period. This property is particularly important for outdoor fabrics, upholstery, and apparel, as they are more likely to be exposed to direct sunlight.
Additionally, sunfast can also be used to describe plants or crops that are resistant to the damaging effects of sunlight. Certain varieties of vegetation are specifically bred or engineered to have a higher tolerance to UV radiation, which helps prevent leaf burn, yellowing, or other forms of sun damage.
Overall, the term sunfast pertains to the ability of a substance, be it a dye, pigment, fabric, or plant, to resist the deleterious effects of exposure to sunlight, ensuring that its color or appearance remains intact for an extended period.
The word "sunfast" is derived from the combination of two words: "sun" and "fast".
The term "sun" originates from the Old English word "sunne", which is further derived from the Proto-Germanic word "sunnon". This ancient root is also related to words in other Germanic languages, such as the Old Norse "sól" and the Old High German "sunna".
On the other hand, the word "fast" comes from the Old English word "fæst", which means "firm" or "steadfast". The origin of "fast" can be traced back to the Proto-Germanic word "fastuz".
When combined, "sunfast" implies something that remains steadfast or unchanging when exposed to the sun. In common usage, "sunfast" refers to materials or pigments that resist fading or discoloration caused by prolonged exposure to sunlight.
