The phrase "grandiose claims" means making exaggerated or overstated statements that sound impressive or important but often lack actual evidence or proof. Full definition
I know of only three or four people looking at this, but they're not well - known because they don't make grandiose claims of looking for a theory of everything. (discovermagazine.com)
«It's trendy for businesses to make grandiose claims about how important design is to them,» she said. (sciencedaily.com)
At first glance, it might seem that we are making grandiose claims for these sacramental rites. (faith.org.uk)