Of native Korean origin. Compare Old Japanese母 (omo, “mother; wetnurse”).
This entry lacks etymological information. If you are familiar with the origin of this term, please add it to the page per etymology instructions.
Particularly: “How is this related to 어머니 (eomeoni)? Is 어머니 (eomeoni) a compound of 엄마 (eomma) + suffixing element 니 (ni), or is 엄마 (eomma) an abbreviation of 어머니 (eomeoni)?”