You can use the word "abstract" to identify a type of art or to describe something that is difficult to explain. But when we talk about the abstract of an article, we mean a brief summary.
Periodical indexes usually include abstracts that are written by the author or by someone at the database company. Since you don't know who wrote them or how accurate they are, you shouldn't quote from abstracts in your papers. Use them wisely and your research will be easier.