Defining terms is essential to scholarly research. Individual Library Research Guides may include alternate disciplinary encyclopedias, dictionaries, handbooks... and scholarly resources. The following databases may be a key resources to find key definitions. Individual reference resources can be identified using the Omni database.
Google Dictionary Wiktionary Dictionary.com Cambridge Dictionary Online Merriam-Webster Word Hippo (thesaurus)
Databases below are a select list of scholarly resources.