1590s, "let out, cause to flow out; draw off (liquid)," by or as by a sluice, from sluice (n.). In gold-mining, "to scour or cleanse by a sluice," by 1859. Related: Sluiced; sluicing.
mid-15c., donour, "one who gives or bestows, one who makes a grant," from Anglo-French donour, Old French doneur (Modern French donneur), from Latin donatorem (nominative donator) "giver, donor," agent noun from past participle stem of donare "give as a gift," from donum "gift" (from PIE root *do- "to give").
As "person from whom blood is removed for transfusion," by 1875; in reference to those living or dead from whom organs or tissues are removed for transplantation, by 1918 (originally of guinea pigs).
1852, "lump of gold," probably from southwestern England dialectal nug "lump," a word of unknown origin [OED]. Another theory is that it is from a misdivision of an ingot. Transferred sense (of truth, etc.) is from 1859.
1570s, "dye obtained from lac;" 1670s as "gold-colored solution of shellac," from obsolete French lacre, name for a kind of sealing wax, from Portuguese lacre, unexplained variant of lacca "resinous substance," from Arabic lakk, from Persian lak (see lac).