A cinquain is a five-line poem that follows a specific syllable or word count pattern. In a syllable cinquain, the first line has 2 syllables, the second has 4, the third has 6, the fourth has 8, and the fifth returns to 2 syllables. Alternatively, a word cinquain uses a structure of 1 word (title), 2 words (describing the title), 3 words (expressing action), 4 words (a phrase or feeling), and 1 word (synonym for the title). This format encourages concise expression and vivid imagery.