EndNote automatically creates lists of words or phrases that may be used repeatedly within an EndNote library, called term lists. Term lists may also be created as needed. They can speed up manual entry of data (using the auto-completion feature) and can help maintain a controlled vocabulary for keywords and other terms. The term list is automatically updated in EndNote so as to stay current with the data that has been entered into the references. New terms entered into a reference will appear in red text. Term lists are stored within a given library and can only be transferred from one library to another by exporting and importing the list; to edit a term list, the library must be open.
To create a new term list:
1) Select Define term lists… from the Library tab menu. The terms list window (below) allows lists to be created, renamed, and deleted.
2) Select the desired delimiters (the punctuation used to separate terms).
3) Once the list has been created, click OK. A library can have up to 31 term lists, with no limit to the number of terms to a list, but each term must be less than 253 characters long.
Linking term lists to fields
Returning to the Library tab menu, select Linked Term Lists. The linking fields with term lists window appears (below). Each field in the generic reference type is listed in the left-hand column, with term list options in the right hand column. Notice that some fields (like Author) are linked to a term list, and others (like Year) are not.
Adding terms
Terms can be added automatically as they are entered by turning on the Update lists during data entry preference (see Setting EndNote Preferences for information on setting preferences). To add terms manually:
1) From the Library tab menu, select Open Term Lists, then open the list of interest (Authors, Journals, or Keywords) 
2) Select New Term on the Terms tab and enter the term in the window provided:
3) Click on Save Term to save and keep the window open so that another term can be added
4) Click on OK to save the term and close the window
Updating term lists
1) Make sure the references from the library to be updated are selected
2) From the Library tab menu, select Open Terms List, and select the desired term list
3) Choose Update List...
4) Select New Term... (see above example) and type in the new term/s to be added
5) Select the field(s) from which to search for new terms 
6) Select Update terms from selected references if references have been selected
7) Click OK
Understanding the journal term list
The journal term list is a multi-column list that may contain up to three different abbreviations for a journal title, in addition to the full name. It is used to perform automatic substitution of abbreviated journal names in formatted bibliographies. A separate journal list needs be created for each library. Note: there will be instances where a journal will not be included in the list, in which case any changes should be made manually to the citation entry or by editing the journal term list.
To import one or more of the files:
Setting term list preferences
To set term list preferences, go to the Preferences option under the Edit menu and Click on the Term Lists option. The following preferences are available (Note: when these features are turned off, they are turned off for all libraries edited on that computer.):
Suggest terms as you type
This is the auto-completion feature. As a term is entered, a suggestion is made (the first matching term in the list). If the term is correct, press the Enter or Tab key to accept it. If a term is entered that is not in the list, it will be in a red font until the reference is closed or saved. (Note: This option is only available in those fields linked to a term list.)
Update lists when importing or pasting references
When this option is selected, term lists are automatically updated as you import, drag-and-drop, or paste references into your library. If this option is turned off, the term lists can be manually updated using the Update List button on the Open term lists command in the Tools menu.
Update lists during data entry
When this option is selected, he term lists are automatically updated as you type in new reference data. If this option is turned off, the term lists can be manually updated using the Update List command in the Terms menu.