A paste, normally used with a toothbrush, for cleaning the teeth.

plural of toothpaste

Alternative form of elephant's toothpaste

A foamy substance caused by the rapid decomposition of hydrogen peroxide using potassium iodide as a catalyst; the outcome of a popular educational experiment in chemistry.

(idiomatic) A situation that cannot be recovered or reversed to its original state.

Alternative form of you can't put the toothpaste back in the tube

Once something is said or done, it cannot be unsaid or undone.

Alternative form of toothpasty