fast
The word fast, as applied to moves in go, has several meanings. In general a fast move has more than one purpose or meaning. For example a fast defensive move might strengthen your own group while threatening an invasion of your opponent's territory. A fast running move may advance your group farther into the center or offer more subsequent options. The opposite of a fast move is a slow move. Fast moves may be thin or loose or light. Fast moves are efficient. Slow moves may be heavy and are inefficient.
Certain openings such as nirensei are known for fast developing moves.
Circumstances calling for fast moves