JMdict entry #1630850

1. noun (common) (futsuumeishi)noun or participle which takes the aux. verb suruintransitive verb starting a train (or bus, etc.) before all the passengers are on board
2. noun (common) (futsuumeishi)noun or participle which takes the aux. verb suruintransitive verb making a snap decision; starting an action without considering objections to it any longer