Tock
One "Tock" is 10 seconds. Tock is a player-invented term and is not referred to directly by in-game help text.
Helix spells, some stat up effects, and some stat down effects (such as Dulling Arrow) work in 10-second tock intervals (as opposed to 3-second tick intervals). Every 10 seconds, the effects will process. Thus, one "Tock" is 10 seconds.
Similarly, Avatar's Favor tiers increase every 9 seconds as opposed to 10.