When a person/organization/whatever noun (#1) feels a rivalry with another person/org/noun (#2), and does everything they can to feel like they are beating the other group, meanwhile person (#2) does not recognize the rivalry at all or does not consider person (#!) a threat.
Named this way because little brothers have a knack for being annoying puntable things
Greg totally has Little Brother Syndrome, when he heard Alysa read 25 pages he read 30 just to be better than her. Little does he know "Learn ABC's with Caillou" is not on par with "War and Peace."
verb
Pulling a little brother is when someone is being very annoying and difficult to deal with, to the point that you want to physically hurt them
Person 1: did you see Azlan today?!
Person 2: yes! He was totally pulling a little brother
The actor/singer/celebrity that could be the little brother or sister of anyone with a little brother or sister, since this person actually was somebody's little brother or sister growing up.
If the singer/actor thought his/her boy/girl next door image was bad, he/she could have always got stuck with the America's little brother/sister image of the other actor/singer/pop star.
The lowlife,poor excuse of an SEC team located in Columbia, SC. USC will always be the little brother of South Carolina and a disgrace to college football. Guess they are an equestrian school now...
The little brother of South Carolina proved their talent once again with their 3-9 season record.
Mars is Earth's little brother planet.
Robots are exploring Earth's little brother.
OpposingFork's Little Brother is a basement gremlin, more commonly known as fork's lil bro. He is a weed dealer in forks neighbourhood, makes 5k$ a week and is plenty rich, buys fork only the finest of bad sandwiches. He gets his weed from OpposingFork's Big Brother, who grows weed in his backyard and cooks 99.9999% pure meth for syrian children, he may be heisenberg but who knows.
OpposingFork's Little Brother is slick jimmy skibid toilet watcher, yea hes a sigma, yeah hes so skibidi, hes so fanum taxxxx, he just wants to be your sigmaaaa, stick out your gyatt for forks lil bro!