Boomer

1. n. One who works up a “boom”.
2. n. One who, or that which, booms.
3. n. A North American rodent, so named because it is said to make a booming noise. See Sewellel.
4. n. A large male kangaroo.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.