[a. OF. verdet (16th c., = Prov. and Cat. verdet, Sp. and Pg. verdete, It. verdetto), dim. of verd VERD sb.]
1. Chem. An acetate of copper (see quots.).
1558. Warde, trans. Alexis’ Secr., 118. Take verdet, or Verdegrise, Vitriol of Almain, and salt Armoniacke. Ibid. (1559), III. I. 53. Take Spanishe greene called Verdet,… Vitrioll, and Alome of eche equally.
1673. Ray, Journ. Low C., 454. At Montpellier the best Verdet or Verdegreece is made,… which is … nothing but the rust or scurf of copper calcined by the vapour of wine.
1863. Watts, Dict. Chem., I. 14. Acetates of Copper.… The normal salt C2H3O2Cu, called also Crystallised Verdigris, Verdet, Cristaux de Venus, is produced by dissolving cupric oxide or common verdigris in acetic acid.
1896. Lodeman, Spraying Plants, 44. Verdet is an acetate of copper. There are many such combinations, all being known under the general name of verdet, or verdigris.
2. A fungus that grows upon maize.
1897. Allbutt’s Syst. Med., II. 801. There seems therefore to be some quality in the maize itself, which when acted upon by the ‘verdet’ as the fungus is called, produces a specific poison.
