carte blanche n.

early 15c., "a playing card," from Old French carte (14c.), from Medieval Latin carta/charta "a card, paper; a writing, a charter," from Latin charta "leaf of paper, a writing, tablet," from Greek khartēs "layer of papyrus," which is probably from Egyptian. The form has been influenced by Italian cognate carta "paper, leaf of paper." Compare chart (n.). The shift in English from -t to -d is unexplained.

The sense of "playing cards" also is the oldest of the French word. The sense in English was extended by 1590s to similar small, flat, stiff pieces of paper. As "small piece of cardboard upon which is written or printed the name, address, etc. of the person presenting it," from 1795: visiting-cards for social calls, business-cards announcing one's profession. The meaning "printed ornamental greetings for special occasions" is from 1862.

Application to clever or original persons (1836, originally with an adjective, as in smart card) is from the playing-card sense, via expressions such as sure card "an expedient certain to attain an object" (c. 1560).

Card-sharper "professional cheat at cards" is from 1859. House of cards in the figurative sense "any insecure or flimsy scheme" is from 1640s, first attested in Milton, from children's play. To (figuratively) have a card up (one's) sleeve is from 1898. To play the _______ card (for political advantage) is from 1886, originally the Orange card, meaning "appeal to Northern Irish Protestant sentiment."

Cards are first mentioned in Spain in 1371, described in detail in Switzerland in 1377, and by 1380 reliably reported from places as far apart as Florence, Basle, Regensburg, Brabant, Paris, and Barcelona. References are also claimed for earlier dates, but these are relatively sparse and do not withstand scrutiny. [David Parlett, "A History of Card Games"]

early 13c., "white, pale, colorless," from Old French blanc "white, shining," from Frankish *blank "white, gleaming," or some other Germanic source (compare Old Norse blakkr, Old English blanca "white horse;" Old High German blanc, blanch; German blank "shining, bright"). This is reconstructed to be from Proto-Germanic *blangkaz "to shine, dazzle," an extended form of PIE root *bhel- (1) "to shine, flash, burn," also "shining white."

The meaning "having empty spaces" is attested from c. 1400. The sense of "void of expression" (a blank look) is from 1550s. Spanish blanco, Italian bianco are said to be from Germanic. Related: Blankly, blankness.

c. 1300, in chess, "a call noting one's move has placed his opponent's king (or another major piece) in immediate peril," from Old French eschequier "a check at chess" (also "chess board, chess set"), from eschec "the game of chess; chessboard; check; checkmate," from Vulgar Latin *scaccus, from Arabic shah, from Persian shah "king," the principal piece in a chess game (see shah; also compare checkmate (n.)). Also c. 1300 in a generalized sense, "harmful incident or event, hostile environment."

As "an exposure of the king to a direct attack from an opposing piece" early 15c. When his king is in check, a player's choices are severely limited. From that notion come the many extended senses: From the notion of "a sudden stoppage, hindrance, restraint" (1510s) comes that of "act or means of checking or restraining," also "means of detecting or exposing or preventing error; a check against forgery or alteration."

Hence: "a counter-register as a token of ownership used to check against, and prevent, loss or theft" (as in hat check, etc.), 1812. Hence also the financial use for "written order for money drawn on a bank, money draft" (1798, often spelled cheque), which was probably influenced by exchequer. Hence also "mark put against names or items on a list indicating they have been verified or otherwise examined" (by 1856).

From its use in chess the word has been widely transferred in French and English. In the sense-extension, the sb. and vb. have acted and reacted on each other, so that it is difficult to trace and exhibit the order in which special senses arose [OED]

The meaning "restaurant bill" is from 1869. Checking account is attested from 1897, American English. Blank check in the figurative sense is attested by 1849 (compare carte blanche). Checks and balances is from 1782, perhaps originally suggesting machinery.