Usually written in kana. Kanji spelling 鈍ちん
dullard (gen. from not picking up on other people's feelings)
Also written 鈍チン
Noun
元もとはと言いえば、健ちゃんが鈍にぶちんなのがいけないんだからね～っ。
When you think about it, it's all Kenny's fault for being so obtuse.