If you describe something such as a loss as grievous, you mean that it is extremely serious or worrying in its effects.
例句
Their loss would be a grievous blow to our engineering industries...失去它們將會是對我們工程行業的一個沉重打擊。Mr Morris said the victims had suffered from a very grievous mistake.莫里斯先生說遇難者因為一個極其嚴重的失誤而遭遇不幸。
ADJ-GRADED
劇烈的；極痛苦的；疼痛難耐的
A grievous injury to your body is one that causes you great pain and suffering.
例句
He survived in spite of suffering grievous injuries.盡管身受重傷，他還是活下來了。
英漢詞典釋義
adv.
極其痛苦地
Having suffered grievously from biological weapons attacks in the past, China supports work that helps comprehensively to strengthen the effectiveness of the convention. It has actively participated in the work of drawing up a Protocol of the Ad Hoc Group of States Parties to the BWC established in 1994, and has made contributions to the progress of the negotiations on the Protocol.中國在歷史上也曾深受生物武器之害。中國支持全面加強《禁止生物武器公約》有效性的工作，積極參加了于1994年設立的公約締約國特設工作組有關制定《公約》議定書的工作，并為議定書的談判取得進展作出了貢獻。
英英詞典釋義
Adverb
1. in a grievous manner;
"the resolute but unbroken Germany, grievously wounded but far from destruction, was able to lay the firm foundations for military revival"