Tick

 TICK n. 1. Interval of time; basic clock time on the computer.
       Typically 1/60 second. See JIFFY. 2. In simulations, the discrete unit
       of time that passes "between" iterations of the simulation
       mechanism. In AI applications, this amount of time is often left
       unspecified, since the only constraint of interest is that caused
       things happen after their causes. This sort of AI simulation is often
       pejoratively referred to as "tick-tick-tick" simulation,
       especially when the issue of simultaneity of events with long,
       independent chains of causes is handwaved.