by gum!

US /baɪ ɡʌm/
UK /baɪ ɡʌm/
"by gum!" picture
1.

おやまあ, あらまあ

an exclamation of surprise or emphasis

:
By gum, that's a big fish!
おやまあ、なんて大きな魚だ!
Well, by gum, I never thought I'd see the day!
まあ、おやまあ、こんな日が来るとは思わなかったよ!