To worry about or be anxious/concerned over something (transitive); somewhat literary or formal in tone.
専門家たちは環境の悪化を憂えている。
Experts are concerned about environmental deterioration.
親は子供の将来を憂えて夜も眠れないと言った。
The parent said they couldn't sleep at night worrying about their child's future.
To lament or grieve; to feel sorrow or lamentation (a somewhat literary usage).
人々は戦争で失われた命を憂え、追悼の意を表した。
People lamented the lives lost to the war and expressed their condolences.
彼は昔の過ちを深く憂えていた。
He deeply lamented his past mistake.