very
Review kanji at the right time with spaced repetition, remember more for longer, and track your progress.
彼の態度は甚だ失礼だ。
His attitude is extremely rude.
その結果は甚だ遺憾である。
That result is deeply regrettable.
計画は甚だ順調に進んでいる。
The plan is progressing extremely smoothly.