You can create a user dictionary, or you can add user dictionaries from previous InDesign or InCopy versions, from files that others have sent you, or from a server where your workgroup’s user dictionary is stored. The dictionary you add is used for all your InDesign documents.
To create a new dictionary, click the New
User Dictionary icon below
the Language menu. Specify the name and location of the user dictionary
(which includes a .udc extension), and then click Save.
To add an existing dictionary, click the Add User
Dictionary icon , select
the user dictionary file, which includes a .udc or .not extension,
and then click Open.
The dictionary is added to the list under the Language menu. You can add words to the dictionary using the Dictionary dialog box.