Which device uses a comparison without the use of "like" or "as"?

The device that employs a comparison without the use of "like" or "as" is a metaphor. A metaphor directly states that one thing is another, creating a strong image and deeper meaning by conveying the essence or quality of the first thing in a more vivid way. For example, saying "Time is a thief" implies that time steals moments from our lives, emphasizing its fleeting nature without the need for a comparative phrase.

In contrast, a simile makes a comparison using "like" or "as," which distinctly marks it as a comparison rather than a direct equivalence. Personification involves giving human traits to non-human entities, which does not focus on comparison but rather on creating relatable imagery. Alliteration is a stylistic device based on the repetition of initial consonant sounds in a sequence of words, which is different from making any kind of comparative statement.