Insightfulnesses is a rarely used word with 16 letters in total. Its correct pronunciation is /ɪnˈsaɪtfʊlnəsɪz/, with four syllables and an emphasis on the second one. The word is formed by adding the suffix "-nesses" to "insightfulness," which means the quality of being insightful. This suffix is used to turn adjectives into nouns, and it also implies the idea of having multiple instances of the quality described by the root word. Although complex, insightfulnesses can be used to describe someone's perception and understanding in various situations.