Lasts 3 of Your Turns

This terminology is used on various aura, e.g. Entangle Terrain, Falling Star. To resolve the effect, add a counter at the end of each of your turns, and dispel the aura when there are 3 counters. If the aura is silenced during your end phase (presumably because it was animated by Enchantress and then silenced somehow), then no counter will be added that turn.