What is the meaning of 0?

The cardinal number zero, indicating absence of any quantity.

A digit in decimal, binary, and every other base numbering system, indicating the absence of any quantity in a given place value.

The identity element with respect to addition.

A Boolean or truth value corresponding to false.

Indicates that the number that follows is in octal.

The pitch of a tone that is more extreme than 1 (higher or lower, depending on local convention; e.g. 0 is the highest tone in Chatino).

Lack of an inherent tone; the pitch depends on the tones of the surrounding syllables.

0.

The origin, starting point, or fixed reference point, especially for a measurement.

The off or low bit state.

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A negation particle (clarification of this definition is needed)

Source: wiktionary.org