Oxymoron is one the most commonly used devices in writing. This literary device creates a sense of contradiction within the intended topic. It's used in literary historical writings like "Romeo and Juliet" by Shakespeare, renaissance poetry, and modern articles.
Usually, it helps to represent the contrasting idea of the author by putting two figures of speech side by side to make them appear in conjunction. Oxymoron is popularly compared to juxtaposition, another commonly used technique that incorporates a contradictory idea with two opposite phrases.
Example: "Why, then, O brawling love! O loving hate", a sentiment of argument in Romeo and Juliet contradicts the common sense against the sentiment of love.
Modern two words Oxymoron could be as follows-
Example: Pretty ugly. Deafening silence, Awfully good or Painful bliss.