Oxymoron

Definition:
An oxymoron is a statement that is
made up of contradicting elements that ultimately invalidate the statement
altogether. This device can be accidental or intentional and can potentially
open up a paradox as well. Oxymorons can also be present in everyday objects,
such as artificial grass and electric candles. 
Literary Example:
"And faith unfaithful kept him falsely true." -Idylls of the King
Visual Example: