quarrelsome
Liking to argue and start fights over small things.
Quarrelsome means quick to argue or complain, always ready to pick a fight over small things. A quarrelsome person turns minor disagreements into major battles, arguing about everything from whose turn it is to erase the board to whether the cafeteria pizza counts as real food.
You've probably met someone quarrelsome: the teammate who disputes every referee call, the classmate who argues with the teacher about every single point on a quiz, or the friend who can't let anything go without debate. While healthy disagreement can spark good conversations, quarrelsome people exhaust everyone around them because they treat every topic like a battle to win.
The word comes from quarrel, meaning a heated argument or complaint. Being quarrelsome is different from standing up for yourself or having strong opinions. Someone with strong opinions might debate ideas they care about deeply, but a quarrelsome person argues just to argue, usually over things that don't really matter. They might start a quarrel about who gets the bigger slice of cake, whether Tuesday or Wednesday is worse, or which superhero could beat which other superhero.
Groups with quarrelsome members often struggle to accomplish anything because they spend all their energy arguing instead of working together.