Flyweight

With a little help from dictionary.com, it is shown that a flyweight has little to do with a fly wheel...

fly·weight
n.

1. 1. A weight division in professional boxing having an upper limit of 112 pounds (50.4 kilograms), between junior flyweight and junior bantamweight.
   2. A boxer competing in this weight division.
   3. A similar weight division in other sports, such as weightlifting.
   4. A contestant in this weight division.
2. Something that is particularly small, light, or inconsequential.