ボケ

ぼけ
noun
blur; comedic setup; senility
entertainmenthealth
1. blur; out-of-focus area
the aesthetic quality of blur in out-of-focus areas of a photograph, now used internationally as a photography term
I took a photo with beautiful bokeh.
To shoot utilizing background blur.
このレンズボケ綺麗(きれい)だ。
This lens produces beautiful bokeh.
2. funny man; straight man's partner
in Japanese comedy (especially manzai), the person who makes absurd statements or acts silly, contrasted with the tsukkomi
The back-and-forth between the funny man and straight man is amusing.
ボケ()
To make a joke/silly remark.
He plays the funny man role in manzai.
3. senility; mental decline
age-related cognitive decline or confusion
ボケ防止(ぼうし)ため(のう)トレしている
I'm doing brain training to prevent senility.
(とし)とってボケてきた。
As I got older, I've become forgetful.
My grandfather's dementia is progressing.

Photography (SENSE 1)

'Bokeh' has been adopted into English as a photography term. It refers to the quality of the out-of-focus areas in an image.

Comedy (SENSE 2)

In manzai comedy, the ボケ makes absurd statements or acts foolish, while the ツッコミ (straight man) corrects or retorts.

Aging (SENSE 3)

Used to describe age-related cognitive decline. Can be considered somewhat casual or even insensitive depending on context.