Definition

A large firecracker or small explosive device, roughly the size of a firecracker but considerably more powerful, producing a significantly louder bang. Historically popular among teenagers, though now illegal or heavily restricted in many jurisdictions due to safety concerns.

Example Usage

The explosion from the M-80 was so loud it set off car alarms three blocks away.

Origin

Named after a military simulator used in training exercises; the commercial version became popular in the 1970s as a novelty item.

Fun Fact

M-80s became so dangerous and associated with injuries that they were banned from consumer sale in the United States in 1966, though they remain available in some other countries.

Source: Definition backfill (hailey)