Some styles, for example an annotated style, include the abstract and some don't.
In Word you can format your bibliography by selecting a style which doesn't include an abstract. See instructions below:
In the document, do the following:
Word: Go to the EndNote tab.
Click on the small arrow on the toolbar next to 'Bibliography'
Select the dropdown arrow next to 'With output style'.
Here, select the output style you'd like to use in the output style dropdown menu. A generic output style you can use for this purpose is the "Author-Date" or Harvard style. Note: To use a style not on the dropdown, in Word, choose "Select another style..." from the dropdown menu.
Click the OK button (or "Update Citations and Bibliography" in Word to format the document using your selected style.