What Does Boomer Mean?

The word boomer is not usually the correct word or the actual word for something but is instead what the thing is commonly called.

For instance:
It is used to refer to the sonic instrument used in ships and submarines to measure the shape and distance of the seabed using a conical beam of sound. The frequency of which is in the approximate range of .5 to 2.5 kHz.

It is used also to refer to the male species of kangaroos because of the sound made by their feet when they move around. In many western countries children born after the Second World War are referred to as part of the baby boomer generation.  

In the United State's Navy Boomer is the slang word referring to a Nuclear Missile armed submarine.
Adult film stars performing in gay films are called Boomers, etc.