The fifth one out of the nine stages of settling the mind into a state of shamatha. Here, one no longer experiences gross flightiness, the subtle flightiness of an undercurrent of thought, or gross or middling dullness. However, because one has overstrained to concentrate and has sunk too deeply inwards, one has relaxed the appearance-producing factor giving rise to the appearance of the object of focus. Consequently, one experiences subtle dullness. One needs to refresh and uplift the mental hold by remembering the benefits of gaining shamatha.
Tibetan: དུལ་བར་བྱེད་པ། dul-bar byed-pa