érthetetlenné
Erthetetlenné is a Hungarian grammatical form. It specifically refers to the past tense, imperfective aspect, definite conjugation of the verb "érthetetlen" which means "unintelligible" or "incomprehensible". This form would be used to describe a situation where something was unintelligible in the past, and the focus is on the ongoing state of incomprehensibility.
For example, "Ez a levél érthetetlenné vált" translates to "This letter became unintelligible." The ending "-né"