What's it called when you claim something?

When you claim something, the act itself is called making a claim, asserting, declaring, or stating. Depending on context, it has more specific names. If you claim ownership of property, it is called staking a claim or asserting ownership. If you claim something in court, it is called filing a claim, bringing an action, or asserting a cause of action. If you claim money from insurance, it is called filing an insurance claim. If you claim that something is true without proof, it might be called an allegation, assertion, or contention. In academic writing, claiming something is called making an argument or thesis statement. In everyday slang, claiming something might be called calling dibs, as in I call dibs on front seat. The person who claims is called claimant in legal and insurance contexts. So what it is called varies, but general terms are claim, assertion, declaration, and demand, with more formal legal terms like petition, cause of action, or demand for relief when claim is pursued officially through institutions.