flat out
phrase · casual
Very busy, or going as fast as possible.
How Aussies use it
- I've been flat out at work all week.
- Sorry I didn't call, I was flat out.
Good to know
'Flat out like a lizard drinking' is a funny extended version meaning extremely busy.
Saying it more formally
In a formal email, essay or the PTE test, use very busy instead.
Slang is great for chatting with friends and workmates, but keep it out of PTE essays and formal writing.