You can chat to contacts in the meeting, if you wish to share information with them without interrupting the flow of the meeting e.g. add to notes. Chats won’t be saved, but can be selected and copied e.g. to a Google Doc if required. Note that chats will be available for everyone in the hangout to see, but anyone joining the meeting will only see chat messages added after they have joined.
To send a chat message in a meeting:
Click on the Chat with everyone button in the bottom-right corner of the screen
If you want all participants to be able to use chat, ensure the option to Let everyone send messages is enabled
Click in the Send a message to everyone line and type your message, pressing Return or clicking on the Send button when complete
If the chat window isn't open and a new chat message is sent from another meeting participant, an indicator will show on the Chat icon. Click on the icon to view the message.