whitish metal element, 1755, coined in 1754 by Swedish mineralogist Axel von Cronstedt (1722-1765) from shortening of Swedish kopparnickel "copper-colored ore" (from which it was first obtained), a half-translation of German Kupfernickel, literally "copper demon," from Kupfer (see copper) + Nickel "demon, goblin, rascal" (a pet form of masc. proper name Nikolaus, compare English Old Nick "the devil;" see Nicholas); the ore so called by miners because it looked like copper but yielded none.
Meaning "coin made partly of nickel" is from 1857, when the U.S. introduced one-cent coins made of nickel to replace the old bulky copper pennies. Application to five-cent piece (originally one part nickel, three parts copper) is from 1883, American English; in earlier circulation there were silver half-dimes. To nickel-and-dime (someone) is from 1964 (nickels and dimes "very small amounts of money" is attested from 1893).