reinforce or support something
buttress - support
The term ‘buttress’ was originally used in architecture in relation to a structure that gives support to a wall or building. It has since been adapted to figuratively express supporting or reinforcing something, such as an idea, argument, position, etc. Often seen in written English, particularly print media.
She buttressed her argument with data she had meticulously researched, making it difficult to dispute her point.
My lawyer worked tirelessly to find evidence to buttress our case and ultimately win an acquittal.
Our latest financial results gave us a degree of financial stability and helped to buttress our position in the highly competitive market.