Cool

The Eleventh Doctor enjoyed denoting various things as cool, such as fezes, (TV: The Big Bang) stetsons (TV: Day of the Moon) and, most prominently, bow ties. (TV: The Eleventh Hour, The Snowmen)

The Twelfth Doctor cited the Eleventh Doctor's usage of the world "cool", among other reasons, as to why he held a low opinion of his predecessor. (COMIC: Terrorformer)