pellet
A small, solid ball or cylinder of material.
A pellet is a small, compact ball or cylinder of material, usually no bigger than a marble. Pellets can be made from many different substances depending on their purpose. Animal feed often comes compressed into pellets that look like tiny brown cylinders. Air rifles shoot small metal pellets instead of bullets. Wood pellets, made from compressed sawdust, can be burned in special stoves to heat homes efficiently.
The key feature of a pellet is its small, dense, rounded shape. Scientists might feed laboratory rats pelleted food that contains precise amounts of nutrients. Ice pellets are frozen raindrops that bounce when they hit the ground, smaller and harder than snowflakes. Some fertilizers come in pellet form so they release nutrients slowly into the soil.
You might also hear pellet used to describe small, rounded droppings from animals like rabbits or deer, which naturally come out in that compact shape. The word emphasizes something small, solid, and usually round or cylindrical, whether it's manufactured or natural.