To check a definition, clarify unfamiliar words, gather background information on your topic, and/or develop your understanding of its terminology, an excellent place to start is to use an authoritative online or hard copy dictionary or encyclopedia.
A Wikipedia entry is not appropriate to cite
as a reference source at university level, but ...
can be useful as a starting point and for background information
can help you create a list of terms or names to research
often includes scholarly references that you can follow up.