a guy
You call a man whose wife has died a WIDOWER.
He is a widower.
a guy
mr. Fredrickson in Up
A man whose wife is dead is called a widower.
a guy
A guy whose about to be shown whose boss
The term is "widower."
A man whose wife dies is called a widower.
A woman whose husband passed away is a widow. A man whose wife passed away is a widower. If the surviving spouse remarries, he or she is no longer a widower/widow.
You would call him a widower (not a frequently used term though).
There is no special name for a woman whose husband cheats on her. The name of a man whose wife cheats on him is a cuckold.