granny swear

V. To swear like a grandmother, or, more generally, like an elderly woman, using phrases such as "dogonit," "fiddlesticks," and other mild interjections such as these.

Grandmother: "Oh fiddlesticks! I burnt the biscuits. Dogonit if this darn oven don't work right."
John: "Wow, granny, don't you know you shouldn't granny swear?"