a short perforated projection on a firearm for holding a percussion cap; a nipple.

a check that protects againt injury, loss, mud, soil, etc; a guard-ring, handle-guard of a sword, mud-guard of a vehicle, etc.

a wall, stacked up sand bags, etc. made to protect something from flood, wind,enemy attack, etc.

a container for dust, rubbish, etc.; a dust-bin.