頓珍漢 とんちんかん
tonchinkan

Noun
na-Adjective

1. absurdity; contradiction; incoherence; irrelevance

Usually Written in Kana
わたくし祖父 そふ みみ とういので、よくトンチンカンな返事 へんじをする。
watashino sofuwa mimiga tōinodeyo ku tonchinkanna henjio suru
My grandfather, being hard of hearing, often makes an irrelevant answer.