Other forms: arguments
An argument is a disagreement between two or more people, but it can also be a statement backed by evidence, like your argument that your school doesn't need a dress code.
Argument comes from the 14th-century French word of the same spelling, meaning "statements and reasoning in support of a proposition." An argument can be a fact used as evidence to show that something is true, like a study that shows exercise improves certain health conditions — an argument for being more active. Argument also means "a discussion between people who have contrary views."