I found his behavior utterly incomprehensible. It's incomprehensible to me that he could have acted that way.
Recent Examples on the WebWave after wave of gestural scribbles in deep blue crayon repeat, like incomprehensible penmanship. Christopher Knight, Los Angeles Times, 1 Sep. 2022 But in some ways, these have been even more incomprehensible and consequential, officials said, underpinning nearly every Kremlin war decision. Catherine Belton, Washington Post, 19 Aug. 2022 But in some ways, these have been even more incomprehensible and consequential, officials said, underpinning nearly every Kremlin war decision. Greg Miller And Catherine Belton, Anchorage Daily News, 19 Aug. 2022 The incomprehensible expanse of reeds emerging from brackish water was teeming with birdlife. Emily Pennington, Outside Online, 16 Aug. 2022 But the debt is also an abstraction—something incomprehensible and alien to Betty Ann’s daily life. Eleni Schirmer, The New Yorker, 27 July 2022 The city many of them saw now was an incomprehensible horror.New York Times, 20 July 2022 Among them were 27 of Qudratullah’s relatives — an almost incomprehensible loss.New York Times, 30 Apr. 2022 At first, the date was written in code: Retail employees had to match each code to a date using a key, but to customers the codes were incomprehensible. Danielle Wiener-bronner, CNN, 17 July 2022 See More
Word History
Etymology
Middle English, from Latin incomprehensibilis, from in- + comprehensibilis comprehensible