A tattoo of the biohazard symbol. Has nothing to do with sexuality, AIDS, or anything else the 13 year old writer of the other definition said.
People get it for any of the following reasons:
1. It looks cool.
2. They are DFLers for the band Biohazard.
3. It goes well into blackwork sleeves due to it's shape.
4. Because they want to.
Bill DeMott has a biohazard tattoo, try calling him gay to his face.