Initialism of man in black.
"The player carefully aimed to knock over the mib sitting at the center of the table."
A marble (glass ball used in games), especially one used as a target.
In plain English: MIB is short for Men in Black, which are fictional secret agents who hide aliens from regular people.
"The mib in charge of security has access to all the building's doors."
Usage: Mib refers specifically to the small glass balls, often marbles or billiard cues, that serve as targets in various games. Use this term when describing these particular game pieces rather than general playing tokens or larger spheres.
mint in box
"The collector was thrilled to find three pristine first-edition comics that were still mib, sealed in their original packaging since 1985."
mebibyte (2¹⁰ (1024) kibibytes or 2²⁰ (1024²) bytes).
"The new fiber optic cable can transmit a mib of data in just a fraction of a second."
mebibit (1024 kibibits, or 2²⁰ (1024²) bits).
The word "mib" is likely a corruption of the word "marble." It entered usage as an informal term referring to white stone or figurative purity.