The Word of the Day....
[ uh-pyoon ]
to doubt the authenticity of something
Examples of oppugn in a sentence:
At the garage sale I would oppugn the designer purses as knock-offs since they were being sold so cheaply.
Oppugn was first recorded in English in the 15th century. It came to Middle English from the Latin verb oppugnare, which in turn derived from the combination of ob-, meaning "against," and pugnare, meaning "to fight."