1. represent or defend, fight for/against
you should stand up for yourself/what you believe in
To 'stand up' for something means to speak or behave in a way that supports something. If you 'stand up for' something or somebody you defend or support a particular idea or person particularly if they are being criticised by others. "I am protesting in order to stand up for the homeless people in our city."If you 'stand up against' something you publicly oppose or defy something or somebody. "I will always stand up against homophobic behaviour in my community."