1. 1〔人〕a fool
    • これを予想できなかったとはなんと僕はばかなんだ
    • How stupid of me not to have foreseen this!
    • ばかは死ななきゃ直らない
    • A fool remains a fool until he dies.
  1. 2〔おろかな事〕
    • 客に無礼な態度をとるようなばかなことはしない
    • I know better than to treat customers rudely.
    • ばかなまねはするな
    • Don't make a fool of yourself.
    • そんなばかなことがあってたまるか
    • That's simply impossible!
  1. 3〔程度が並外れていること〕
    • ばか安い[高い]値段で
    • at 「a ridiculously cheap [an exorbitant/an unreasonable] price
  1. 4〔用をなさぬこと〕
    • この鍵はばかになっている
    • This key won't work anymore.
  1. 馬鹿と鋏はさみは使いようEven fools and blunt scissors can be useful in the hands of a clever person.
  1. 馬鹿にする〔あなどる〕look down on;〔軽視する〕make light of
    • 自分の父親をばかにしてはいけない
    • You shouldn't 「laugh at [make fun of] your own father.
  1. 馬鹿につける薬はないThere is no cure for a fool.
    • 彼はばかに出来ない男だ
    • He is not a person to betrifled with [made light of].
    • 彼の反対はばかに出来ない
    • His objection can't beshrugged off [passed over] lightly.
    • 毎月の食費がばかにならない
    • My monthly food expenses run up to a considerable sum.
    • 月々3万円の余分の収入はばかにならない
    • An extra thirty thousand yen a month is not a sum to be sneezed at.
  1. 馬鹿の一つ覚えA fool always tries to show off the only thing he knows.
  1. 馬鹿も休み休み言えDon't 「talk nonsense [be silly]!
    • 1時間も待ってばかを見た
    • I wasted a whole hour waiting for her.
    • こんな古い家を買ってばかを見た
    • I should have known better than to buy such an old house.
  1. 馬鹿話idle [silly] talk
    • ばか話をする
    • have a silly conversation/talk idly