The Collaborative International Dictionary of English v.0.48:

Aquatint \A"qua*tint\, Aquatinta \A`qua*tin"ta\, n. [It.
   acquatinta dyed water; acqua (L. aqua) water + tinto, fem.
   tinta, dyed. See Tint.]
   A kind of etching in which spaces are bitten by the use of
   aqua fortis, by which an effect is produced resembling a
   drawing in water colors or India ink; also, the engraving
   produced by this method.
   [1913 Webster]