What it means
A playful, catch-all word for any grotty little bug that's going round. When someone's sniffing and sneezing but it's nothing dramatic, they've got the dreaded lurgy. It's the phantom plague that excuses you from school or work with a melodramatic groan, even if you just fancy a duvet day.
Usage examples
"I can't come in today, I've got the lurgy."
"Stay away from me, I don't want your lurgy!"
"Half the office is off with the lurgy this week."
Where it comes from
Coined by Spike Milligan and Eric Sykes for a 1954 episode of The Goon Show, 'The Lurgi Strikes Britain', as a made-up disease. The nonsensical name stuck, leapfrogging from radio comedy into the nation's vocabulary as shorthand for any mystery lurgy that's doing the rounds.