丧偶
When someone is widowed, it means their husband or wife has died. In Chinese, we use the verb 丧偶 (sàng'ǒu) to describe this situation. It literally means 'to lose a spouse'.
For example, if you want to say 'She is widowed,' you can say '她丧偶了 (Tā sàng'ǒu le).' The '了 (le)' here indicates a change of state.
You might also hear people say '他失去了妻子 (Tā shīqù le qīzi)' which means 'He lost his wife,' but 丧偶 is a more direct and common way to express being widowed.