What is a key characteristic of onomatopoeia?

A key characteristic of onomatopoeia is that it involves a word that imitates the sound it represents. This means that the word's pronunciation closely resembles the actual sound associated with the action or object it describes. For example, words like "buzz," "bang," and "sizzle" effectively mimic the sounds of a bee, an explosion, and the cooking of food, respectively. This auditory quality makes onomatopoeia a vibrant linguistic tool for adding depth and realism to language, particularly in poetry and descriptive writing.

The other choices pertain to different literary devices: similes utilize comparative language with "like" or "as," metaphors make direct comparisons without those words, and alliteration involves the repetition of consonant sounds at the beginning of words. Each of these serves distinct purposes but does not capture the essence of onomatopoeia, which is fundamentally about sound imitation.