The word "nemawashi" is often used among gardeners, and it means digging around the roots of a tree, to prepare it for transplant.
This process involves bringing dirt from the new location, and introducing it to the tree before the transplant, so the tree can grow accustomed to the new environment before it gets there.
Also, many people who do business with or work for Japanese companies are familiar with the term "nemawashi", since it refers to a commonly-used Japanese consensus-building technique in the business world. It is often cited as an example of a Japanese word that is difficult to translate effectively, because it is tied so closely to the Japanese culture itself.
The primary purpose of a meeting, as viewedby people from western countries, is to reconcile conflicts, reach a group judgment or decicion, or solve problems. These are activities that require discussion and debate. Thus, it is assumed that the main activity during a meeting will be the sharing of opinions, and the attempt to reconcile those that differ.
By contrast, the Japanese idea of a meeting is that it's an opportunity to confirm things that have already been decided elsewhere, and to report and share information. This conception of a meeting contains little room for discussion or debate. The participants at the meeting are not required to actively participate or share their opinions. There are few surprises. Therefore, they require an informal process of laying the foundation and building a consensus of opinion before the meeting.
The nemawashi meeting itself may be either formal or informal. At one extreme, it could be buttonholing someone in the hallway or elevator, or stopping by their desk to chat. It might be something along the lines of, "By the way, I wanted to tell you about something I've been working on..." It could be brought up casually over a semi-social occasion, such as lunch or dinner or drinks or while playing golf. Or, it could be an explicitly-planned meeting specifically for the purpose of discussing the topic.
One very formal type of nemawashi is the "pre-meeting", which takes place before a larger, more structured meeting. At a pre-meeting, any issues planned for discussion in the larger meeting that might prove to be controversial are hashed out ahead of time, so that they don't create embarrassing snags. Any new ideas or proposals that are going to be presented can be floated at the pre-meeting, in order to avoid any surprises during the main meeting.
Now, you might notice that the concept of a meeting differs between Japanese and non-Japanese people. Even some Japanese people have a negative imageof nemawashi, that it is a kind of going behind one's back or playing a dirty trick, but it's actually a process to make business run more effectively and smoothly, like tree transplanting.