I’m not sure if this custom extends past the South. Or if families still call a single male sibling Brother.
My great Uncle was called Brother within our family his entire life. He had five sisters. All long dead now. But my Mom still refers to him as Brother because thats what her mom called him.
I guess perhaps the reverse is true? A family member would be known as Sister in a large male family?
Is this still commonly practiced?
I’ve known only one person in my life whose nickname was ‘Brother.’ ‘Bubba,’ now is a different story.
I don’t think I’ve personally known of a girl called ‘Sister’ (other than nuns). “Sis,” however, is quite commoon.
Just anecdotal, FWIW.
We have three kids, two boys and our youngest (6) is a girl. We call her sis or sissy.
My father was one of three brothers with one sister. Everybody in the family, including their parents, called her “Sis”.
Since I expect most replies to this will be anecdotal, let’s move it over to IMHO.
Colibri
General Questions Moderator
I didn’t realize Sissy was a Nick for Sister. Makes sense now that I think about it.
I have never heard of this.
I’ve lived in the south most of my life and never heard of this.
I never encountered anyone calling a sibling Brother or Sister except when referring to them as “my brother/sister” - I have 3 sisters and one brother, and we have always been called by name, nickname, or an appropriate insult. 
I have two brothers. Both my brothers and my parents refer to me as ‘Sis’ sometimes. I’m from New Zealand, so perhaps a bit further south than this thread was expecting.
When we moved South, my sister was asked if she was going to call her two children Bubba and Sissy, nicks for brother and sister. Of course, down here they call their grandmothers Meemaw, so…
StG
My niece calls her sister “Sister” because she’s 2 and she can’t quite pronounce sister’s name.
My younger sisters both called me “bubba”, because that is how they initially pronounced “brother”. Occasionally they still do, but not as a matter of course. My parents called us by name. I find that nicknames derived from the suffix are more common - “Junior” or “Little (name)”, “Trey” (for III), extc.
I have 3 siblings, and I’m the only boy. I also have several male friends with similar circumstances and have never heard this particular nick name.
Of course my parents might refer to me to my sisters as “your brother” since I’m their only one. Otherwise, they just call me by my name/shortened-name.
I’m from south-east Michigan.
ETA: Though, one of my good friends who’s an only boy (with 2 sisters) has the nickname “bubby” within his family. His dad’s side is from the south. It never occurred to me until now that’s probably a twist on “bubba”. Huh.
I have one brother and one sister. I call my sister Sissy in writing, but rarely when actually talking to her. I call my brother “Little Brother” from time to time, mostly to emphasize that I’m 11 yrs older than he is.
My parents called us all by our names or nicknames. None of us was referred to as sister or brother by our parents.
My cousin has two children. An older girl and boy. The boy still refers to his sister as ‘Sissy’ and she uses a shorter version of his name. That’s also how my cousin refers to her daughter, as Sissy.
That’s a little creepy. Berenstein Bears creepy.
And Grandfather is PawPaw.
Always wondered and this thread is as good a place to ask as any other…
Is the “aw” sound in Meemaw and PawPaw pronounced like the “aw” in “Awww, shucks”? Or are the names written like that but pronounced like mee-ma and papa?
“Aw” as in “Awww, shucks.” Accept no substitutes. 