also: おおぼけ
noun
great idiot; fool; something silly or stupid
Used to describe a person who is extremely foolish or an action/statement that is outrageously stupid. Often used in a joking or exasperated manner.
See also: 惚け
彼は大ボケで、いつも変なことばかり言っている。
He's a great idiot, always saying weird things.
そんな大ボケな発言、信じられない。
I can't believe such a stupid remark.
Combination of 大 (おお, 'big') and ボケ (from 惚ける/呆ける, 'to be foolish/senile'). The exact historical derivation is uncertain, but it follows a common pattern of intensifying a noun with 大.