Uncount

Children accomplish learning how to count, and then almost immediately they have to learn how to 'uncount', that is, subtract.

The jar rocks and falls, allowing the mice to 'uncount' themselves from the jar. The large mouse turns out to be a rock and the snake is left hungry.

For example, the term abuse would require at least one definition for the uncount usage ‘invective, insulting language’, and another for the count usage ‘an item of invective, an insult’.