What would you call the husband of a widow? [duplicate]

My suggestions, having read the comments and agreeing with some.

The [late] husband of the woman in the big house down the street must've liked his gadgets a lot!

You can only omit 'late' if she has not remarried.

If you were/are a friend of the woman/couple then it is more tactful to use his name.

I like working in your garden because your James had all the tools I need.

If you are employed as a gardener then either you wouldn't know that her husband was deceased or she would explain something like, "These are my late husband's tools." In that case you simply use the same phrase that she used.

In addition to "late husband", answered by chasly, I suggest "deceased husband" which sounds better than "departed" or "defunct" and is more "polite" than "dead" as you would like.

deceased - no longer living; dead.