Meaning of “gesenu(解せぬ)”
“Gesenu(解せぬ)” means “I can’t understand”.
This is an old word, kind of Samurai word or so.
You can sometimes see this word in Manga or Anime or Movie.
We hardly use this word.
But these days something “old” is kind of “cool” for young people.
So now, “gesenu(解せぬ)” is an old word, but also kind of a slang.
When some people want to try to make the conversation funny, sometimes use this word.
A: Guess what? Rika asked me out on a date!!
B: What? She also asked me…
A: What’s going on???
B: Don’t have a clue.
A: … Ge…Gesenu(解せぬ)!!