érthetetlenségüket
érthetetlenségüket is a Hungarian word, a form of the noun érthetetlenség, meaning "unintelligibility" or "incomprehensibility." The suffix "-üket" indicates possession by a third-person plural subject and marks the object of a verb. Therefore, érthetetlenségüket translates to "their unintelligibility" or "their incomprehensibility" when used as a direct object.
This word would typically appear in a sentence describing a situation where something belonging to a group