The Collaborative International Dictionary of English v.0.48:

Coinage \Coin"age\, n. [From Coin, v. t., cf. Cuinage.]
   1. The act or process of converting metal into money.
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            The care of the coinage was committed to the
            inferior magistrates.                 --Arbuthnot.
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   2. Coins; the aggregate coin of a time or place.
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   3. The cost or expense of coining money.
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   4. The act or process of fabricating or inventing; formation;
      fabrication; that which is fabricated or forged.
      "Unnecessary coinage . . . of words." --Dryden.
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            This is the very coinage of your brain. --Shak.
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WordNet (r) 3.0 (2006):

coinage
    n 1: coins collectively [syn: coinage, mintage, specie,
         metal money]
    2: a newly invented word or phrase [syn: neologism, neology,
       coinage]
    3: the act of inventing a word or phrase [syn: neologism,
       neology, coinage]