khak·i / ˈkakē/ • n. (pl. khak·is) a textile fabric of a dull brownish-yellow color, in particular a strong cotton fabric used in military clothing. ∎  (khakis) clothing of this fabric and color.

khaki a textile fabric of a dull brownish-yellow colour, in particular a strong cotton fabric used in military clothing. Dating from the mid 19th century, the word comes from an Urdu word meaning ‘dust-coloured’.
Khaki Election informal name for the British general election of 1900, used in reference to the South African War of 1899–1902, and later also applied to the general elections, such as 1918, in which military action was a key issue.

khaki dull-brownish yellow; fabric of this colour. XIX. — Urdu ḵākī dusty, f. ḵāk (— Pers.) dust.