n. Younger sibling or cousin of the same sex, as younger brother or male cousin of a male, or younger sister or female cousin of a female; sibling or cousin of the same sex of the junior line, whether older or younger. Cf. kaina, Gram. 2.7. Koʻu kaikaina, my younger sibling. hoʻo.kai.kaina To claim a kaikaina relationship; to act as a kaikaina, to address and treat as kaikaina, as from affection. (PPN t(e,a)hina.)
Yesterday we learned the word for older sibling of the same sex so it’s only appropriate that we learn the term for a younger sibling or cousin of the same sex. That word is kaina, or you will more than likely hear kaikaina. Same meaning. I remember when I had a set of twins in one of my Hawaiian language classes and they didn’t have Hawaiian names, I named one Kuaʻana and the other one Kaina. Older sister and younger sister. It is 20+ years later and they still use those names!
Don’t forget, the Hawaiian concept of family relationships is different from Western thinking. When speaking about siblings you need to consider, for siblings of the same sex, whether they are younger or older and use the appropriate terms.
ʻAʻohe oʻu kaikaina – I don’t have any young siblings the same sex as me.
He kaikaina ko koʻu kaikunāne – My brother has a younger brother.
ʻElua kaikaina o Kalaʻi – Kalaʻi has two younger sisters (Kalaʻi is a girl).
He Momi e Lei ai (a pearl to wear as a lei) 
Aloha nui loa e Kumu!! Mahalo no koʻu inoa Hawaii🙏❤️
We just lost our true friend and loyal family member Kaikaina after almost 12 years together. We initially got him to be Bear’s little brother and so named him Kaikaina. He was absolutely perfect in that role. He also was a wonderful, smart, sensitive, loving dog. Bear died on July 14th this year (2019). Kaikaina missed him terribly and was a different dog, except as always loyal to me and mommy. He was depressed. We got him 100% medically checked one week after Bear passed. He passed with flying colors…nothing wrong.
He slowly started to stop eating like he used to. after many vet visits and trying to get him to eat anything we could think of, we took him in again on Tuesday. Exactly 45 days after Bears passed we found out he had succumbed to cancer, his liver was shot, his gall bladder was shot, and he had jaundice. So, we lost our Kaikaina. He is and will always be missed. He taught me far more than I ever taught him.
Hi last 45 days were us spoiling him every day. He went on walks, he went camping on a mountain lake with us, he was brushed almost every day. And he was hugged and petted for hours and hours when we got home from work.
He’s running with Bear again right now. We named our new puppy Kupa’a Kaina in honor of Kaikaina.
What a beautiful moʻolelo! And a most appropriate name for your new baby!