We found one dictionary that defines the word swear on one's mother's grave:

General (1 matching dictionary)

1. swear on one's mother's grave: Merriam-Webster

▸ Words similar to swear on one's mother's grave ▸ Usage examples for swear on one's mother's grave ▸ Idioms related to swear on one's mother's grave ▸ Wikipedia articles (New!) ▸ Words that often appear near swear on one's mother's grave ▸ Rhymes of swear on one's mother's grave ▸ Invented words related to swear on one's mother's grave