Dhyana means the state of meditation

"Dhyana (meditation per se) is the continuous flow of the mental processes toward the object (of meditation)."
Yoga Sutra

"Dhyana is the continuous flow of reflection [i.e., ‘mirroring’] with respect to the essential reality of the object (of meditation)."
Ratnatika, a tantric text

The mental laser
Dhyana is an effortless flow of the mind spontaneously directed toward the object. Dhyana (meditation) is a dynamic process: during it, the mental processes (thoughts, ideas, etc.) are turning around the object of meditation, making free associations (for example) related to that particular object only. During meditation, the activity of the mind reaches a tremendously dynamic intensity and eventually becomes a laser-beam-like stream of concentrated thinking.