How to explain "Cool" to a Briton

I was recently having a conversation with a friend from England. During the conversation I described someone as being cool, but he seemed confused by the term and asked me what I meant.

I couldn't really explain to him that well what it would equate to in UK English. Does anyone know of a good way to explain "cool" to someone who isn't familiar with the term?

People in England know lots of meanings for the word cool. As a personality trait, it can mean aloof, trendy, laid-back, sound, or accomplished, and probably many more things too, even before you start thinking of its meaning more widely. Each of these meanings can be quite distinct from the others.

If someone from the UK was asking you what you meant, they were either seeking clarification or being contrary.

Maybe you could choose a meaning from the above words or, -- to be facetious for a moment, -- find someone more co-operative to talk with?

Examples of these different usages:

• Doris has always been warm and giving, but Eva is often a little cool. [aloof]
• Is this where the cool kids go? [trendy]
• No, you're fine. He is cool with high-test peroxide. [unanxious]
• Don't worry about him deceiving you, he's cool. [sound]
• He is one cool accordion player. [accomplished]

'Cool' is one of those words whose signification has shifted (in my (English) experience) more often than most. In the 1950s it meant Miles Davis and sharp suits. In the 60s this carried on into the mod image, but also came to be applied to anything from Che Guevara to patchouli oil. More lately, smartphones, tablets are all described as 'cool'.

What does 'cool' mean? Perhaps unflappability in the face of overwhelming complexity.

It completely depends upon the inflection you give the word "cool" and the facial expressions that accompany it as well. An example of such was done with the word "dude" in 'Dude Where's My Car'. Cool can mean many different things if you want it to.