(chemistry) An azo dye used as an acid-base indicator for titrations involving a weak base

(chemistry) A cationic dye, prepared from coal tar and creosote oil, often used in epifluorescence microscopy.

(organic chemistry) An organic reagent, most commonly used as a tetrasodium salt as an indicator for metal titrations.

A reddish-orange colour used to set things apart from their surroundings, especially in the aerospace industry.

plural of orang-utan

Alternative spelling of orangutan

plural of orange tip

Any of various pierid butterflies having orange tips to the upper forewings, especially Anthocharis cardamines, of Eurasia.

plural of orange stick

Dated form of orangutan.