The definition of seat-of-the-pants is slang to describe something improvised, or done based on prior experience or by feel.
If you don't prepare for a speech but you just get up improvise it, this is an example of when you are doing it by the seat-of-your-pants.
Slang using or relying on intuition and experience rather than instruments, technology, or a predetermined plan
Origin of seat-of-the-pantsfrom by the seat of one's pants (see phrase under seat)
- Based on or using intuition and experience rather than a plan or method.
- Performed without using instruments: a seat-of-the-pants landing of the aircraft.
- fly by the seat of one's pants