aunt-in-law

Noun

aunt-in-law (plural aunts-in-law)

1. The wife of one's uncle or aunt (parent's sibling).
   • Between uncle and aunt-in-law, or uncle's wife, you have a connection of affinity, and you have the same between aunt and uncle-in-law, or aunt's wife. [sic]1871, William Lindsay, Inquiry into the Christian law, as to the relationships which bar marriage, page 86
2. The aunt of one's husband.
   • Petunia would later become an aunt-in-law to Harry's wife Ginevra Weasley and a great-aunt to Harry and Ginny's three children; James Sirius, Albus Severus,2009 August 28, contributor, Petunia Dursley, Harry Potter Wiki
3. The aunt of one's wife.