Which of the following terms describes comparisons made without using "like" or "as"?

The term that describes comparisons made without using "like" or "as" is metaphor. A metaphor directly refers to one thing by mentioning another, suggesting they are alike in a significant way. For example, saying "Time is a thief" implies that time stealthily takes away moments from our lives, similar to how a thief would take possessions. This creates a vivid image that conveys deeper meaning and connection between the two ideas.

Similes, on the other hand, make comparisons using "like" or "as," which is why they don’t fit the definition here. Analogies often explain complex ideas by comparing them to more familiar concepts, but they aren't limited to the succinct comparison that defines a metaphor. Personification attributes human characteristics to non-human entities, which is also a different function from making direct comparisons. Thus, metaphor is the most accurate term for this type of comparison.