The Kardashian/Jenner matriarch reportedly filed an application with the U.S. Patent and Trademark Office to register the phrase, which she uses as a hashtag in most of her posts on Instagram.com, especially in reference to her six children.

Kris reportedly wants to use the #ProudMama phrase for advertising purposes, but a jewellery company, owned by Jenny Present, already owns the name Proud Mama, and trademarked it back in 2009, editors at TMZ.com report.

Jenny's lawyer says he will "vigorously" protect his client's rights.

A representative for Kris has yet to comment.