Sixteen can be used interchangeably with "copy". Meaning that you understand completely.

Most commonly referred to someone's age. It is said to be one's "Prime," age, where they look/shine/feel their best. Sixteen is the age where you get multitudes of exciting privileges such as quickie-driviers' license, get a decent job (Host/hostess,) and you're no longer at the very "bottom" of highschool.

The age when everything you've already been doing becomes legit.

n. a celebratory shout issued after a successful homosexual orgy

An abbreviation for M-16, the standard issue assault rifle among U.S. Forces. The M-16 is a gas-operated, rotating bolt rifle chambered for the 5.56 x 45 round. Magazines are typically either 20 or 30 round clips, though high-capacity magazines and drums are also available, though somewhat jam prone. The M-16 went through a number of improvements during its lifetime, the most modern version, the M-16A2, is very reliable, though its Soviet counterparts, the AK-47, the AKM, and the AK-74 all have far superior reliability, particularly in poor conditions. The earliest version, the M-16, had chronic reliability issues, but was capable of semiautomatic or full automatic fire. The newer M-16A4 and M-16A2 are only capable of semiautomatic or burst fire, but lack the constant reliability problems which earned the M-16 the nickname “Mattel 16.” It should be noted that the M-16A1 and the M-16A3 are also capable of automatic fire, but these weapons are less common. A “civilianized” version of the M-16, the AR-15 is also manufactured, but it is capable of only semiautomatic fire. The AR-15 is criticized by anti-gun activists due to its origins, light weight, and ease of modification. In recent years, as the Army clears out M-16A2’s and A1’s in favor of the M-16A4 and eventually the OICW, a growing number of obsolete M-16’s are owned by gangs and organized crime.