あほ(な)

fool; stupid; idiot

Word type: 

Kanji: 

阿呆(な)

Standard: 

ばか(な)

Standard kanji: 

馬鹿(な)

Example: 

おまえ、ほんまにあほやなあ。
You know, you're really an idiot.

あほなことばっかり言うてんと、早よ仕事しぃ。
Stop talking garbage and get back to work.

Commentary: 

According to some research on あほ and ばか, people in Kansai tend to feel that あほ is much softer than ばか, while people in Kanto feel the opposite. However, whichever word you use, the feeling depends on how you say it, so be careful.