Knackered
What it really means
Very tired, exhausted. One of the most common ways British people describe being worn out after work, study or a long day.
Context, tips & common mistakes
Knackered is the standard British word for exhausted — stronger than tired, interchangeable with 'shattered', and safe in almost any spoken context including casual work chat ('I'm absolutely knackered after that deadline'). It extends to objects too: a knackered laptop or a knackered washing machine is one that has stopped working properly.
Register notes: it is informal, so keep it out of essays and formal emails, but nobody blinks at it in the office kitchen. If someone says they are knackered, the sympathetic reply is light — 'get an early night!' — not a medical enquiry. And the intensifier order runs: tired, knackered, absolutely knackered, dead on my feet.