Toothpaste is a semi-solid substance.
While it has a thick, paste-like consistency, it exhibits properties of both liquids and solids.
Toothpaste can flow and take the shape of its container, similar to a liquid. However, it also holds its shape and doesn't spread out like a liquid.
This unique characteristic makes toothpaste a colloid, a mixture where tiny particles are dispersed evenly throughout a liquid.
In toothpaste, the solid particles are suspended in a liquid base, giving it its semi-solid texture.