It might happen that there is a need to express negative emotions towards others. Or it might happen that others do this to you. In those cases it is useful to understand some Japanese offensive words. Please use these with care.
Fool or idiot
バカ (baka)
Fool or idiot, used in Kansai
アホ (aho) - writing unsure
Doing something untimely
まぬけ (manuke)
A slow person
のろま (noroma)
Being bad at something
下手 (heta)
Being very bad at something
下手糞 (hetakuso)
A stingy person
ケチ (kechi)
An old man
ジジイ (jijii)
An old woman
ババア (babaa)
Not being cool
ダサイ (dasai)
Fussy or depressing
ウザイ (uzai)
Creepy
キモイ (kimoi)
Drop dead!
くたばれ (kutabare)
Get out of the way!
どけ (doke)
Noisy!
うるさい (urusai)
These words are mostly used by young people