Definition
to collaborate in shared efforts to complete necessary tasks
共同努力；协力合作；参与
During the community cleanup event, everyone mucked in without hesitation to help out.
在社区清洁活动中，每个人都毫不犹豫地参与进来帮忙。
In this project, we need every team member to muck in to ensure its successful completion.
在这个项目中，我们需要每个团队成员都参与进来，以确保其成功完成。
To prepare for the annual performance, all the actors decided to muck in and share the rehearsal tasks.
为了准备年度演出，所有演员决定一起参与并分担排练任务。