definition tundish
tundish(Noun) A funnel (usually) used in smelting, foundry work etc. tundish(Noun) A funnel used to create a siphonic break in a drainage system and/or provide visual indication of flow, usually in an overflow line. tundish(Noun) A wooden dish or shallow vessel with a tube at the bottom fitting into the bunghole of a tun or cask, forming a kind of funnel used in brewing.