Flat strap Australia informal
This phrase is sometimes hyphenated.
Having a lot to do
Being flat-strap with his part-time job, he neglected his study.
At maximum speed, efficiency, or power
He ran flat-strap to the crime scene to see who was killed.
We are working flat-strap to complete the project on schedule.
Very busy
Being extremely busy or hardworking
If something is packed to the gills, it is completely full.
To do or solve a variety of work or problems at the same time.
Used to say that you are busy and can only do a limited amount of things at once
The phrase's origins may be traced back to the used of "strap" in horseback riding.