Is there any particular word for a person whose partner (love) has passed away? Like he/she is keeping lonely now, crying or silent all the time because they miss their dead partner.
Dictionary.com: (of a person) greatly saddened at being deprived by death of a loved one
Merriam-Webster: suffering the death of a loved one
Cambridge: people who are sad because someone close to them has died
Oxford: be deprived of a loved one through a profound absence, especially due to the loved one’s death
"Just because we're bereaved doesn't make us saps!" - Walter, The Big Lebowski
Possibly a widow.
a woman who has lost her spouse by death and has not remarried
As Hugh mentioned below, a man who has lost his wife and not remarried would be a widower.
a man who has lost his spouse by death and has not remarried