A bomb is an explosive device. A blockbuster is colossal bomb, capable of demolishing an entire city block.
In film industry parlance, the term “bomb” is used metaphorically to describe a movie that fails at the box office. But contrary to expectation, a “blockbuster” movie isn’t a colossal failure, but rather a colossal success.
What other pairs of established metaphors are similarly illogical or contradictory? (Metaphorical terms only, please! No run-of-the-mill oxymorons, or non-metaphorical reversals such as “you drive on the parkway but park on the driveway”.)
In the linguo of finance, a rainy day is a bad day that drains your wealth but a rainmaker is a person who consistently brings in wealth (brings in wealthy clients).