Is a spouse responsible for their deceased spouse's debt if it is in the deceased party's name only?

The spouse is not responsible for the debt but the estate of the deceased is responsible. In a very simple situation she would pay his debt with his money before she inherits it.

This will depend on the state ( if in the US) there are many states where they would have possible liability, depending on the type of debt also.

If the spouse is the executor of the will he/she would have to pay it. If he/she wasn't, then whoever was would have to pay off any debts before the spouse (and any other heirs) would receive their portion.

Didi