mourn
v.v. to feel or show great sadness because someone has died. You can also use it when you lose something very important to you.
v. to feel or express deep sorrow following a death or a significant loss. Often implies a period of public or private grieving.
The whole country began to mourn the loss of their leader.
She took a week off work to mourn her father and handle his final affairs.
While some cultures mourn in silence and isolation, others celebrate the life of the deceased with communal feasts and vibrant music to help the living process their grief.
From Middle English mornen, mournen, from Old English murnan, from Proto-Germanic *murnaną. Cognate with French morne (“gloomy”).
The verb can be used transitively ('mourn someone') or intransitively ('mourn for someone').