Tim Bowen keeps his cool as he tackles this cool little word.

Apart from its usual meaning of ‘rather cold’, the adjective cool can also mean ‘calm and relaxed’, as in ‘We admired her cool handling of the situation’, and ‘not friendly or enthusiastic’, as in ‘He got a rather cool reception from the audience’. 

It can also be used to mean ‘impressive because it is attractive or fashionable’, as in ‘He’s one of Britain’s coolest young designers’, and, in spoken English, it can be used for agreeing to something or saying that something would be convenient, as in ‘We could go and see a film’. ‘OK. That would be cool’.

If you play it cool, you behave calmly and do not show your emotions, so that people do not know what you are thinking or feeling.

As a verb cool is used to mean either to become cooler or to make something cooler, as in ‘We opened the windows to cool the room’. If a feeling or emotion cools, it becomes less strong, as in ‘I suggest we wait until tempers have cooled a little before we continue’. 

Used with the definite article, the noun form of cool refers to the pleasant cool temperature of a place or time, as in ‘We went for a walk in the cool of the evening’. The uncountable form of the noun refers to the quality of being extremely fashionable or sophisticated, as in ‘In my eyes, she was always the absolute embodiment of cool’.

If you keep your cool, you remain calm in a difficult situation but if you lose your cool, you become angry in that situation, as in ‘As soon as he started speaking I completely lost my cool’.