Also found in: Dictionary, Thesaurus, Medical, Encyclopedia.
To enter into some position, activity, or situation to intervene or improve it. We'd still be dealing with this mess if the manager hadn't stepped in and figured out a solution. We have a new marketing specialist stepping in to try and turn the company's profits around. You're here as an observer, but if you see a situation in the classroom, please step in.
step in (to the breach)
Fig. [for someone] to assume a position or take on a responsibility when there is a need or an opportunity to do so. The person who was supposed to help didn't show up, so I stepped into the breach. The manager stepped into the breach when Jane got sick.
step in(to some place)
to walk into a place. Tiffany stepped into the room and said hello to everyone. She stepped in to say hello.
Enter into an activity or situation; also, intervene. For example, The business was doing poorly until Stan stepped in, or They are going to make a mess of the mailing unless someone steps in and shows them what to do . [Late 1400s] Also see step into.
1. To enter into an activity or a situation: A substitute stepped in for the injured player.
2. To intervene: The government stepped in to end the strike.