idiot, moron, nimrod

April Fools' Day

Someone who has poor handwriting, especially poor knowledge of writing kanji characters, due to habitual use of Japanese computer text input methods rather than pen and paper.

Alternative spelling of 馬鹿野郎 (“stupid man; prick; dick”)

having a comeback or excuse for everything one is told, being smart in the sense of having a smart mouth

(idiomatic) silence is golden, better left unsaid

blink of an eye, in nothing flat (a very short period of time)

(idiomatic) needless to say, goes without saying

(idiomatic) needless to say

Alternative form of 言うは易く行うは難し