If you call someone a fool, you are indicating that you think they are not at all sensible and show a lack of good judgment.

Fool is used to describe an action or person that is not at all sensible and shows a lack of good judgment.

If someone fools you, they deceive or trick you.

If you say that a person is fooling with something or someone, you mean that the way they are behaving is likely to cause problems.

In the courts of kings and queens in medieval Europe, the fool was the person whose job was to do silly things in order to make people laugh.

Fool is a dessert made by mixing soft cooked fruit with whipped cream or with custard.

If you make a fool of someone, you make them seem silly by telling people about something stupid that they have done, or by tricking them.

If you make a fool of yourself, you behave in a way that makes other people think that you are silly or lacking in good judgment.

If you say to someone 'More fool you' when they tell you what they have done or what they plan to do, you are indicating that you think that it is silly and shows a lack of judgment.

If you play the fool or act the fool, you behave in a playful, childish, and foolish way, usually in order to make other people laugh.

If you fool around, you behave in a silly, dangerous, or irresponsible way.

If someone fools around with another person, especially when one of them is married, they have a casual sexual relationship.

If you fool around, you behave in a playful, childish, and silly way, often in order to make people laugh. In British English, you can also say you fool about .