Widow Witch

"So every old woman who lives in the forest alone is a witch?"

—Märchen von Friedhof, Märchen

When a woman is mysterious and solitary, at least in terms of a husband. The town community will probably shun her, calling her a witch. In a fantasy story it might be true as she is a Wicked Witch who wanted to get rid of her husband so she cast a spell to help things get going or perhaps there is a curse on her family that makes it so they lose men. If the story is not one of fantasy, the witch impression might just be the vibe the old women give of as she is in mourning for her late husband.

The whole thing exists because of the Unfortunate Implications of the similarities between widows and witches. It is understandable that the neighborhood would feel that she's creepy if the woman still dresses in black and her only friends are women or she only lives with women. Although her lack of interaction with men might be because she's not actually interested or they aren't interested in her because she's as ugly as a witch like the Fag Hag. Other similarities include tending to the herb garden that reminds her of all that is living and healthful, having a cat because it's easy to take care of and will keep her company, being very old and unwell, being bitter towards people as the widow is old an lonely and laughting wicked because she's out of touch with reality.

She was probably a very devoted wife like the Yamato Nadeshiko who is perhaps especially sad because she wasn't able to have children, they never visit her, or they won't even get her out of the house.

Contrast Cute Witch, Hot Witch and Determined Widow.

Examples of Widow Witch include:

Anime and Manga

Averted Trope when it comes to Syaoran's Hot Mom Yelan in Cardcaptor Sakura. She just doesn't fit the trope description despite being a magician and a widow, since she is also a Hot Mom and a Defrosting Ice Queen.

Film

Practical Magic has Sandra Bullock playing the part of a Widow Witch... same curse as below.
In Eve's Bayou, Mozelle is a fortuneteller and hoodoo practitioner whose husbands have a tendency of dying. This isn't always the result of a curse, however. One husband was murdered by her secret lover when they fought over her.

Literature

Nanny Ogg from the Discworld novels. She's had three husbands, "and that's only the official score." A jolly old woman with a lot of children, mostly by said husbands, it's unlikely she did anything to get rid of them. (It's also not clear how many of them are dead. Sobriety Ogg is, but in Thief of Time, Death comments that witches are matrilinear because they find it easier to change men than change names, possibly suggesting the traditions of witchcraft include quickie divorces.)
In Snow White and Rose Red, by Patricia C. Wrede, the Widow Arden fits this.
In The Sun Witch, the Fyne sisters are cursed so that their husbands die.
In John Updike's The Witches of Eastwick, the women of the village of Eastwick only gain powers after their husbands/significant others either die or divorce them.
In Sweet Valley Twins #3 The Haunted House they think a witch lives in the neighborhood who keeps her husband chained up in the attic.
Another series for young girls is Babysitters Little Sister, spin off to The Baby Sitters Club where in the first book, Karen's Witch, she is sure that the neighbor, Mrs. Porter, who dresses all in black is a witch. It's never stated what her marital status is but the girl never considers that the black might be for mourning, not being wicked. In fact, Mrs. Porter is actually very kind, hosting a Halloween party for the neighborhood kids, and letting Karen pick a goldfish out of her pond.

Live-Action TV

In El Chavo del Ocho, this is played with La bruja del 71 ("The Witch from the [Apartment] 71"), whose appearance, antics and bad judgment on pet naming makes everyone in the neighborhood (especially the children) think she is a witch; however, she has been presented as an old spinster. Averted with DoÃ±a Florinda, who is a widow, only much younger and just bitchy.
Grams of Charmed is a widow for at least her first husband, Alan, who died. She went through a few more husbands after that.
Willow of Buffy the Vampire Slayer is a good witch (mostly) who look the part

Tabletop Games

In Witch Trials, one of the available suspects is a widow who, according to the flavor text, "has buried three husbands and is working on the fourth". Not that this means much in terms of her supposed witchiness; two other suspects have "uncharacteristically nice for his age" and "is suspiciously persistent in her claims for innocence" on their cards.

Video Games

In City of Heroes, every member of The Cabal (except for Kattie Hannon, who was a child at the time) is a widow because their enemies the Red Caps killed all of the men in their village.