Tick

In WoW:
In World of Warcraft:
 * 1) A time increment used for over time effects (Channeling, DoT, HoT, etc.):
 * 2) * 1 tick is every time the spell's overtime effect happens. Many effects tick once every two seconds, but not all.
 * 3) The bronze drake Tick guarding the Caverns of Time together with Chronalis and Occulus.

In Not-WoW (aka Real-Life):
Not specific to World of Warcraft, but sometimes used to describe time increments, a tick can have a few meanings:
 * 1) From Jargon at Speechcode.com: Interval of time; basic clock time on the computer. Typically 1/60 second.  See http://www.speechcode.com/jargon/jargon.info.Jiffy.html JIFFY].
 * 2) From Wikipedia: In computing, the duration of one tick of the system timer interrupt. Typically, this time is 0.01 seconds.

Note: 1/60 = 0,01(6).