Adjective

1. happening at regular intervals
2. happening at the same time; isochronal
3. of or pertaining to the use of clocks derived from the same clock reference

   Their entire national telephone network is isochronous, with a clock distribution tree radiating from a single, protected cesium reference clock.

4. of or pertaining to data associated with time sensitive application

   These packets belong to an isochronous voice application and need priority handling.