D defs.my
Entry 1 sense Webster, 1913

Slacken

/slăk'-ən/ · Slack·en · IPA /ˈslæ.kən/
01 n. A spongy, semivitrifled substance which miners or smelters mix with the ores of metals to prevent their fusion.
  1. 1.
    A spongy, semivitrifled substance which miners or smelters mix with the ores of metals to prevent their fusion.(Metal.)