From hkaaw "his/her grandchild, grandson, granddaughter" with added me- for "your".
This form mostly seen in Tiipay, but also found in Barona, listed as 'ehkaaw or nyehkaaw, "my grandchild". According to some speakers, hkaaw is specifically, "his/her daughter's child". Similar to 'Iipay paahkaly, "his/her daughter's child".