Updated: Jan 12, 2020
When talking about zanshin in karate, it refers to the fact of adopting a state of active relaxed and permanent vigilance, keeping the attention on what is happening, and what can happen, because nothing at any time is definitive, and always we should expect some change.
This word comes from a Japanese word that means:
zan: stay, follow, continue, save, preserve.
shin: heart, spirit, attention, will.