loud and brash but with little meaning
bombast - bluster
The word ‘bombast’ refers to something, particularly speech or writing, that is considered pretentious and showy. While it is designed to seem important and impress people, such things are devoid of any real substance or significance. The term is almost always used in a negative context and to express disapproval.
Mary leads through example rather than words and takes a studied approach to everything. She displays no bombast at all.
Rather than delve into potential policies or suggest reasoned solutions to current issues, the two political candidates instead offered nothing but bombastic statements in the debate.
I don’t want to take a subtle approach to promoting this product. I want a big, bombastic ad campaign that will grab people’s attention.