I am not a native English speaker, but I found these four words are interesting, I believe most people are familiar with the first two, but even so, hardly have any chance to use them. Maternal love or maternal instinct is often used, but you wouldnt write paternal aunt in a form, when you take your nephew to hospital, would you? A simple aunt would suffice, surely not adding on fathers side.

Paternal and maternal are in my dictionary for some time, but recently, I was wondering how would one much more precisely refer to two nieces who were born to two different siblings, a brother and a sister, of the person?

Of course, he or she can say, this boy is my brothers daughter and the other my sisters. Just for the sake of unnecessary use of words that we never use in everyday life as a normal person, how would you describe the relationships?

I believe that I have found the words for them: fraternal and sororal.

They sound odd to use in these cases, especially with fraternity and sorority in your mind, itd be a bit hard to picture how to use these words.

So, one can say he is my fraternal nephew, meaning my brothers son, at least according to Wiktionary. Im not sure if Wiktionary can be credible source, because Ive not found any other online dictionaries that have long history in print list that term.

From Oxford dictionary:

paternal maternal
2 [attributive] Related through the father: 1.2 [attributive] Related through the mothers side of the family:
fraternal sororal
1 Of or like a brother or brothers: Of or like a sister or sisters:

The following relationships are clear to understand:

  1. Paternal aunt/uncle/grandparents
  2. Maternal aunt/uncle/grandparents

But not these if Wiktionary is still in question:

  1. Fraternal nephew/niece
  2. Sororal nephew/niece

Without clear relationship definitions, it is supposed to read as my brothers nephew, which sounds utterly odd, because your brothers nephew certainly is your nephew or your son. Itd be fine if using fraternal son, but there is no nephew in the words.

By the way, these two words can also be used to describe twins, but sororal only informally for females. Did I smell inequality? For boy or girl? Both boys have to share the term with boy and girl twins, but both girls have their own term, though informal. Unequal, thats for sure for the dictionary of my spell checker, it doesnt even have sororal.

I wonder what my brotherly nephew and my nephew, brotherly mean, same as brothers nephew and even weirder, right? Looking at the four words, sororal is the only one not in the form of -aternal. Words are interesting, aint they?