1A conjunction meaning 'but' or 'however', introducing a statement that contrasts with what came before. Slightly more formal than しかし, common in writing and formal speech.
彼は有能だ。だが、人付き合いが苦手だ。
He is capable. However, he's poor at getting along with people.
計画はいい。だが、予算が足りない。
The plan is good. But the budget isn't enough.
彼女は来ると言った。だが、結局現れなかった。
She said she would come. Yet in the end, she didn't show up.
雨は止んだ。だが、風はまだ強い。
The rain has stopped. Still, the wind is still strong.