Flat spin

To be in a flat spin means to be in a state of confusion or disarray and dates from the early 20th century. Before this, from the late 18th/early 19th century, people’s heads or minds would simply get in a spin, which meant a state of dizziness or confusion. The notion of flat spin came much later, from aeronautics when an aircraft in trouble would descend in low, spinning spirals, which became known as a flat spin.