Excessively articulate. Also as noun (with the and plural agreement): people who are too articulate as a class.
1920s. From over- + articulate.
To articulate or pronounce too carefully or precisely. Also more generally: to express or present with unnecessary or excessive detail or care.
1920s; earliest use found in Harold Edward Palmer (1877–1949), linguist and teacher of languages. From over- + articulate.