Which word is used to describe something that provokes laughter?

The term that describes something that provokes laughter is "risible." This word originates from the Latin "risus," which means "laughter." When something is labeled as risible, it indicates that it is amusing or capable of causing laughter, often in a humorous or light-hearted context.

In contrast, the other words convey very different meanings. "Serious" refers to something grave or earnest and does not evoke humor. "Melancholic" describes a feeling of deep sadness or gloom, which is opposite to humor. "Indifferent" indicates a lack of interest or concern, again, not associated with provoking laughter. Therefore, "risible" is the appropriate choice, as it is directly linked to humor and the act of making people laugh.