first water

noun
1.
(formerly) the highest degree of fineness in a diamond or other precious stone.
Compare water (def 13).
2.
the finest quality; highest rank.
Origin
1745-55
Examples from the web for first water
  • The permits are the plant's first water quality operating permits.
  • The wine region's first water came from an ancient aquifer.
  • When a twenty-first water molecule joins the cage, however, the structure becomes unstable.
  • Seven feet lower, and the first water shortage ever would have been declared in the river's lower basin.
  • During approach for the first water landing at a large nearby pond, he did not notice that the wheels were still extended.
British Dictionary definitions for first water

first water

noun
1.
the finest quality of diamond or other precious stone
2.
the highest grade or best quality
3.
the most extreme kind: a fool of the first water