A selection of ways to describe personal relationships, with usage comments based on in-universe lore and conversations with Mando realists, rounded out by learning about different kinds of family structures around the world. Your experience with how these are used among other Mando realists and in fan fiction will vary, but these definitions are a decent starting point for one way to use the words we have and for exploring ideas in discussions. The order is somewhat based on closeness in the personal relationship, to most distant.
See also Marriage, Military ranks, Pronouns, Teacher.
vod: sibling/cousin in your family (specifically); member of your squad. Less commonly used to refer to any member of the family, regardless of age or biological/adopted relationship, including a spouse (a cultural feature added by Drew Karpyshyn in Star Wars The Old Republic: Revan). When not used to address or refer to someone in particular, it can mean "a member of the Mandalorian culture." Some of the clones adopted this word into Basic to refer to other clones who they considered to be Mandalorian posers. Depending on context, it might simply indicate biological or adopted status in the family, and not speak to the quality of the relationship. Vod can be used sarcastically, as seen in the phrase Copaani mirshmure'cye, vod?
vod'ika: used in a similar way English might use "dear sibling." It is only used affectionately, only used with people you consider part of your family, and only used among equals. It can be used regardless of age, and is used to indicate a good-quality relationship. (In the books, I've only seen it used as a term of endearment toward a single person, but I suppose it could be used in the plural to talk about multiple people that a person is close to.)
riduur: spouse. Use this to refer to a person with whom you are in a long-term, committed, intimate relationship. If you terminate the relationship (called shuk'la riduurok), there is no common term for your former spouse, though the fanon dar'riduur (no-longer-spouse) would be an appropriate term to use if you needed to explain why you don't want to be around someone.
cyar'ika: darling, sweetheart. This term of endearment, according to the books, can be applied to anyone you have a deep connection with, including parents, children, spouses, and pets (per a passage in Republic Commando: True Colors). However, among fans of the language, it is only used between lovers, spouses, and (very occasionally) the closest of friends. Based on the original dictionary, I suspect that the plural of this word is cyarese (KT's spelling: cyare'se), which means "beloved ones."
'ika: Added to the end of a short or shortened version of a name to turn the name into a term of endearment. This is often translated as "Little [Name]," but is more like "Darling [Name]" or "Beloved [Name]," except without the usual saccharine overtones that such a phrase has in English. Add this suffix to just about any adjective or noun to get an affectionate name (in a few cases, adding 'ika to a word turns it into a new word with a specific meaning, so be sure to check the dictionary before using the new term to make sure you're saying what you think you're saying). For example, mesh'ika is "beautiful one" and atin'ika is "tenacious one." Only used among family members, important mentors, very close friends, and (probably) pets. If I recall correctly from the books, using this term flippantly or sarcastically could get you hit by offended party. In the books, it only seems to be used by an older person to a younger person (we mostly see parent to child); sibling to sibling; and between spouses. On Earth, most people use it in a similar manner. Be sure you are confident in the depth of your relationship with another person before using this term of endearment!
ori'vod: older sibling/cousin. Use this to refer to someone who is both a peer in your family and who is older than you are and/or who you admire for their advice and assistance.
kih'vod: younger sibling/cousin. Use this to refer to someone who is both a peer in your family and who is younger than you are and/or who you often offer advice and assistance to. Also an appropriate word to talk about a niece/nephew/nibling/child of a sibling.
buir: parent. In Mandalorian society, this person has the primary responsibility for the care and upbringing of a Mando (child or adult). The clones and some Mando realists use this to refer to their biological or adoptive parents as well as to favorite mentors. Buir can be tacked on to the end of a short or shortened name as an honorific. Traditionally, Mandos don't care about blood relationships. If they care for the children of their spouse as their own, then they are a buir. Thus, this word can also be used to refer to a stepparent. If the stepparent does not provide care for the children, but is still respected, then use ba'vod (or ba'vodu, depending on dialect). If the stepparent has few redeeming qualities, use their first name (if allowed). Vod is also a way to call anyone who is a member of your family, regardless of their actual relationship with you. As a bland way of describing them, use riduur be buir. To be insulting, use aruetii o'r ner yaim (outsider in my house). Note that in traditional Mando culture, a buir never stops being a buir unless they fail in their duties and the child declares that person a dar'buir (no-longer-parent). At that point, the child no longer looks to the person for financial or physical support, because none can be expected, and refers to that person as if they were a stranger. Note that young children likely have a different way of referring to a parent, but the original author never provided this; fan suggestions include buu, bubu, and bui, among others (and this nickname may even vary by family).
jatne'buir: Best-parent. Use this as an affectionate term for a mentor, beloved parent, or special parent-figure.
ba'vod (KT's spelling: ba'vodu; some dialects use the original spelling only as a term of endearment): parent's sibling. In the books, this seems to be used to refer to someone of the parent's generation who is willing to help out with some parenting duties. Thus, you can use this to refer to a mentor or a beloved older person who is not your parent.
ba'buir: grandparent. In the books, this is used to refer to a literal grandparent. On Earth, it has been suggested that it's an honorific for older Mandos who are respected for their experience and the wisdom they can dispense because of it.
ad: child. This generic term can refer to a descendant, offspring, or adoptee of any age. Use a possessive pronoun or possessive phrase to describe the person's relationship to you or someone else. This can also be used to refer to someone else's children, either by context, or by describing the relationship; for example, another way to refer to a niece or nephew would be ad be ner vod (child of my sibling).
ad'ika: little one. Use this to refer to your mentee or child or as a term of endearment for someone you feel parental affection for (even if you are not that person's parent or mentor).
burcya (KT's spelling: burc'ya): friend. This is for someone who you have a very good relationship with, but who is not a member of your family. Mandos in the books and sometimes in real life on Earth have used word this sarcastically.
cabur: guardian. Use this to refer to people who regularly help or encourage you but are otherwise not close to you.
tomad: ally. This isn't used in the books, and I rarely see this come up in any of the servers that I'm in. My personal preference is to use this to refer to someone who is occasionally helpful or inspiring to me, but who I don't consider a "friend" and is definitely not someone who I consider family.
alor: leader. This word is suitable for leaders, instructors/teachers, subject matter experts, and those who are in charge of projects, communities, events, Discord servers, etc.
jatne vod: sir, ma'am, gentlebeing, etc. Servants and waitstaff use this as a polite honorific for patrons who they don't know the name of. When used to refer to someone that you do know the name of, it is a sarcastic honorific.
narudar: temporary ally. Someone who is normally an outsider, but you're getting together with them to complete a project.
aruetii: outsider, traitor. Normally, this simply refers to anyone who is not part of the Mandalorian culture. Of course, flinging this term at someone who considers themself to be a Mandalorian is a grave insult. When using it to refer to a non-Mandalorian, it is a neutral term, like addressing someone "stranger." Add an insult adjective or use with an insult phrase to emphasize the negative connotation.
A few terms of endearment can apply to your peers. The generally accepted ranking of these terms, from closest to you to farthest, is as follows.
cyar'ika
vod'ika
vod
burcya
tomad
Some people have a strong desire to specify the gender of people they have a relationship with. This essay looks at how to do that, why not to do that, and what to do instead.
A brief video about a few kinds of extended family structures on Earth: https://www.youtube.com/shorts/CKC0k74HFcM
Fan ideas about kinship words in Mando'a:
https://www.tumblr.com/ranahan/772190628635344896/i-made-some-cleaner-images-and-installed-gimp
Suggested kinship tree from the above thread: https://64.media.tumblr.com/925ad54cb43ad4e29177aa21f7191325/f2a59c6e92201daa-af/s540x810/6072bf73c933838f7e3162d9a0755fdfc881b6cb.jpg