"513" is a term primarily used colloquially as an internet slang and acronym. It is derived from the numerals '5', '1', and '3', which are combined to form the term. This numerical arrangement has various meanings and interpretations depending on the context it is used in.

One common meaning of "513" is often associated with the marijuana culture. It is believed to be a code used to discreetly refer to the use or consumption of cannabis. The number '5' is said to signify the letter 'E', '1' represents the letter 'A', and '3' represents the letter 'C'. When put together, it forms the abbreviation 'EAC', which stands for "Enjoying A to the C" or "Enjoying All Cannabis".

Additionally, "513" is also used occasionally as a general slang term among friends or online communities. It can be used to express an inside joke, secret code, or a unique greeting that individuals may have created within a particular social circle.

Due to its informal nature and prevalence in internet culture, the term "513" may have different interpretations depending on the context in which it is used. Therefore, its meaning is subject to change based on the individual or community employing it.