This is a metaphor. Anyone's steps cannot BE thunder, they can sound like thunder or they can represent thunder to the frightened listener. A metaphor is a figure of speech where a word or phrase is attached to an object or action to which it can't be literally applicable.Steps cannot BE thunder. In everyday speech "you're an angel" is an example of a typical metaphor.
The speaker and the listener both know that the listener is not actually an angel, but is being likened to one because of his/her actions. A metaphor directly refers to one thing - the steps - by mentioning another - thunder. By using such a literary device, it may identify hidden similarities between two ideas.
The fluorescent light was the sun during the test is an example of a metaphor. A metaphor is used to state that one thing is another thing, so the light was the sun. Metaphors are used many times in poetry; however, they are also used in literature, and often musical lyrics and the use of the metaphor will make your language more colorful.
An example would be “life is a highway,” There is also the simile to consider. While the metaphor states that one thing is another thing, the simile says that one thing is like another thing. An example would be the metaphor that love is a battlefield and the simile would be love is like a battlefield.
A metaphor is a figure of speech which refers to one thing by mentioning another thing. Some examples of metaphor are as follows: If you wanted to say that a person is angry, you can say that “He/She is boiling mad.” If you wanted to say that the exam was easy, you can say “the exam was a breeze.” Metaphors are commonly used in literature such as in William Shakespeare’s Shall I Compare Thee to a Summer’s Day when he used the words “But thy eternal summer shall not fade…”, in John Keats’ When I Have Fears when he used the words “Before high-pil’d books, in charact’ry hold like rich garners the full-ripened grain,” and in Kate Chopin’s The Storm wherein she mentioned “Her mouth was a fountain of delight.”