Have you ever searched your brain for a word to describe what you are trying to express, but you just couldn’t find one? Maybe it’s because there’s not a word for it at all.

In the English language, there is a name for such words: lexical gaps. A lexical gap, also known as a “lacuna” or “accidental gap,” is a word in a language that could exist because it follows the grammatical rules of the language but is nonexistent. In addition, the word missing from one language may often be present in another.

For example, the Indonesian word mencolek describes the trick of tapping from behind on the opposite shoulder of another person to confuse them. Sadly, there is no English equivalent for the word, so we must instead resort to using a long string of words.

Here are 10 of the most well-known lexical gaps in the English language.