"powerful person," 1670s, from Great Mogul (1580s), the common designation among Europeans for the Mongol emperor of India after the conquest of 1520s, from Persian and Arabic mughal, mughul, alteration of Mongol (q.v.), the Asiatic people. As a name for the best quality of playing cards, by 1742, so called for the design on the back.
A Motion was made on behalf of the plaintiff for an injunction to restrain the defendant from making use of the Great Mogul as a stamp upon his cards, to the prejudice of the plaintiff, upon a suggestion, that the plaintiff had the sole right to this stamp, having appropriated it to himself, conformable to the charter granted to the card-makers' company by King Charles the First [Blanchard versus Hill, High Court of Chancery, Dec. 18, 1742]
1729, "jester, merry fellow, one who jokes," agent noun from joke (v.). In generic slang use for "any man, fellow, chap" by 1811, which probably is the source of the meaning "odd face card in the deck" (1868), also often jolly joker. An 1857 edition of Hoyle's "Games" lists a card game called Black Joke in which all face cards were called jokers.
American manufacturers of playing-cards are wont to include a blank card at the top of the pack; and it is, alas! true that some thrifty person suggested that the card should not be wasted. This was the origin of the joker. ["St. James's Gazette," 1894]
c. 1200 (as a surname), "one who cards wool," agent noun from comb (v.). Meaning "a long, curling wave" is 1840, American English, from comb (v.), in reference to a wave, "roll over with a white foam" (1808), which is perhaps from resemblance to a fowl's comb.
also RSVP, by 1825 ("It is the custom among persons of the first rank in London, to add at the bottom of their invitation cards, R.S.V.P."), from French initialism (acronym) of répondez, s'il vous plait "reply, if you please," as it might be written on a letter or envelope.
Old English dælere "divider, distributor; agent, negotiator," agent noun from deal (v.). Meaning "player who passes out the cards in a game" is from c. 1600; meaning "one whose business is to buy and sell merchandise" is from 1610s. Meaning "purveyor of illegal drugs" is recorded by 1920.