Samyama means holding together or binding or integration. It comes from the Yoga sutras when one combinees concentration, mindfulness, and non-dual awareness.
I think the most helpful term for this is absorption — when the sights and sounds fill your being and you dissolve into the experience of just this. This is a state conducive to peace and happiness.
There is an illustrative story of how to access this state: A student and master are on a walk. The student thinks the master has been hiding something from him: the secret to enlightenment. On the walk he hears the song of a bird. And the master says “Did you hear that? That’s the secret.” And the student realizes everything.