5 common idioms that mean the opposite of what you think - from blood is thicker than water to fat chance

Language is always changing, and that means that words and their meanings can sometimes transform, and  some words can even be lost over time. There are, therefore, some commonly used phrases which may not mean quite what you think.

Below, we look into the origins of five phrases and idioms and reveal what they actually mean and what their intended purpose was when they were first introduced.

To learn even more about the language and etymology, check out our dedicated words and meanings page and also articles such as unusual English phrases explained: meanings and origins of 14 idioms such as ‘break a leg’, also origins of 15 idioms such as ‘get off your high horse’,  origins of 16 idioms such as ‘piece of cake’ and 12 idioms with unexpectedly sinister origins.

Blood is thicker than water

What you think it means: People use this phrase when they mean to say that the relationships between family members are more important than the bonds created between people who are not related to each other.

What it actually means: The original version of this phrase is actually “the blood of the covenant is thicker than the water of the womb” which was referring to the bond between armed forces soldiers, and that it is stronger than family alliance.

Great minds think alike

What you think it means: This phrase is used positively when people realise they have had the same idea as someone else, usually at the same time as them.

What it actually means: The idiom is incomplete, with the full phrase being ‘great minds think alike, but foolish minds rarely differ’. This is rather insulting and essentially means that two people will come up with the same thought if they both have the same limited knowledge.

A rolling stone gathers no moss

What you think it means: People use this phrase to mean that someone who is always working or doing something will not become lazy or bored. It’s generally thought to be a good thing that people are always working.

What it actually means: The saying is said to date back to Roman times, and actually it was meant to be a negative when people were always on the go because this meant that they did not have time to set down foundations or form relationships.

Curiosity killed the cat

What you think it means: The saying is used to mean that people shouldn’t ask too many questions or snoop around to get information that is not voluntarily given to them as they will get hurt by what they find out.

What it actually means: This is actually only half of the phrase. The full phrase is actually ‘curiosity killed the cat, but satisfaction brought it back’, which means that although being curious may lead to some pain there is still something positive to be gained from it because it’s always better to know the truth.

Fat chance

What you think it means: Taken literally, this phrase could be interpreted to mean that there is a high chance or something happening.

What it actually means: Even though something which is ‘fat’ is characteristically large, the phrase actually means that there is an extremely small chance of something happening.