- n. a dull, yellowish-brown colour, the colour of dust.
- n. a strong cloth of wool or cotton, often used for military uniforms, used as a school uniform color.
Khaki is everywhere; if you don’t own a pair of pants in that universal dust color, then you at least own a pair of pants in a different color that you still refer to as “khakis.” Unlike a lot of military fashion, which is still the province of people dumb or crazy enough to wear them when getting groceries (camo pants, etc), khakis are one military export that everyone seems to have accepted into mainstream fashion and culture.
Khaki was a color before it was a pair of pants: The Hindustani ख़ाकी (xākī) and the Persian خاک (xâki)) refer to that which is “dusty, earthy, or earth-colored.” In fact, Hindustani got it from Urdu, which got it from Persian to begin with, khak in Persian meaning “dust.” Its absorption into English occurred in the mid-18th century, after the color was introduced in British soldiers’ uniforms in India; Lieutenant Harry Lumsden “invented” it for the Guide Corps in 1846.
One can’t imagine why else the color would be used except for camouflage is anyone’s guess, but it apparently was not widely used for camouflage by Western wearers until half a century later, during the Boer Wars (1899-1902); these were two short wars fought between Britain and the Boer states (Orange Free State and Transvaal Republic) in Africa. Other sources indicate that the khaki uniform was official as early as 1867, during the Abyssian campaign (when Britain smacked around the crazy King Theodore a bit (the King committed suicide after the British trounced his army). From what I can tell, the color was used officially in campaigns, but didn’t become official service dress until the turn of the century. The United States Army adopted in around this same time for the Spanish American War
The kind of color that “khaki” as a uniform indicated, however, managed to shift as it was adopted by various militaries, most noticeably taking on a much greener hue—what we would now refer to as “olive drab.” Most military uses of the word will refer to any one of a number of more greenish hues, though civilian use still refers to the canonical dust color.
Khakis as referring to a pair of trousers is a relatively recent invention, dating back to the 1950s, when the phenomenon came to civilian fashion. Though of course at first these were necessarily dust-colored, the word has changed over time to refer more to the style of pants rather than the colors; I, for instance, find myself referring to “my black khakis” or even, ridiculously, “my khaki khakis,” which makes me die a little inside.