tatum
The shortest statistically significant time interval between successive notes in a rhythmic phrase or a musical piece.
In general, the music meter contains a nested grouping of pulses called metrical levels, where pulses on higher levels are subsets of the lower level pulses; the most salient level is known as the beat, and the lowest level is termed the tatum.
Where it comes from
Coined by American computer scientist Jeffrey A. Bilmes in 1993, initially as a blend of temporal + atom, but deliberately changed from tatom to tatum to honor master jazz pianist Art Tatum, who was known for his exceptional celerity.
Adapted from the Wiktionary entry tatum (CC BY-SA 4.0).