Definition of bosh:
- Empty talk; contemptible nonsense; trash; humbug.
- Figure; outline; show.
- In forging and smelting, a trough in which tools and ingots are cooled.
- One of the sloping sides of the lower part of a blast furnace; also, one of the hollow iron or brick sides of the bed of a puddling or boiling furnace.
- The lower part of a blast furnace, which slopes inward, or the widest space at the top of this part.