c. 1300, "ash, cinders; dust of the earth;" early 14c., "pulverized substance;" mid-14c., "medicinal powder;" late 14c. as "gunpowder," from Old French poudre "dust, powder; ashes; powdered substance" (13c.), earlier pouldre (11c.), from Latin pulverem (nominative pulvis) "dust, powder" (see pulverize). Specialized sense "gunpowder" is from late 14c. In the sense "powdered cosmetic," it is recorded from 1570s. The insertion of the unetymological -d- was common in French (compare meddle, tender (adj.), remainder).
In figurative sense, powder keg is first attested 1855. Powder room, euphemistic for "women's lavatory," is attested from 1936. Earlier it meant "place where gunpowder is loaded on a warship" (1620s). Powder horn attested by 1530s. Powder puff first recorded 1704; as a symbol of femaleness or effeminacy, in use from at least 1930s.
Powder blue (1650s) was smalt used in laundering; as a color name from 1894. Phrase take a powder "scram, vanish," is from 1920; it was a common phrase as a doctor's instruction, so perhaps from the notion of taking a laxative medicine or a sleeping powder, with the result that one has to leave in a hurry (or, on another guess, from a magician's magical powder, which made things disappear).
Avis dropped an exhausted little heap onto her aunt's bed. She put her hand over her heart and said piteously, "Oh, Aunt Joyce, I mustn't ever do that again. My heart's going awful fast. I shall have to take a powder. Wasn't it fun though-" Avis' dark eyes flashed. [from "The Evolution of Avis" in The Connecticut School Journal, Jan. 9, 1902]
When the wife of your breast has confessed she has drest
On just triple the sum you allowed her,
And has run up long bills for her frocks and her frills--
Take a powder, my friend, take a powder.
[from "The Panacaea," in Punch, Dec. 14, 1901]