Brilliant

You can use it as a one-word reaction. If a friend suggests getting pizza, just say Brilliant!. It also works as an adjective for people or things. You might describe a brilliant book or a brilliant scientist. It is very flexible and always positive. Just don't overthink it—if you like it, it's brilliant.

Use it when you receive good news. It is perfect for confirming plans over text. Use it at work when a colleague solves a tricky problem. It works when you are eating a delicious meal. It is also great for showing enthusiasm without being too dramatic. It feels warm, energetic, and very British.

Avoid using it for very solemn or sad occasions. Don't say brilliant if someone tells you they found their lost keys after five hours—it might sound sarcastic. In very formal US business settings, it might sound a bit too enthusiastic. Also, don't use it for small, boring facts. Saying brilliant because someone told you the time is a bit much.

Historically, it referred to the physical light of a diamond. In the 20th century, the British adopted it as their go-to superlative. It reflects a certain British charm—being impressed but staying articulate. It is now a linguistic badge of the UK. Even the most cynical Londoner uses it daily.

In the UK, you will often hear mega-brilliant for extra emphasis. Some people shorten it to brill in casual texts. You might also hear absolutely brilliant to show 100% agreement. In Northern England, it might be paired with dead as in dead brilliant. It is the cousin of words like superb or fantastic.