Synonyms of 'bluster'
1 boastDictionary, swagger, talk big (slang)
He was still blustering, but there was panic in his eyes.
2 roarDictionary, storm, bully
hot airDictionary, boasting, bluff
the bluster of their campaign
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A bluff is an attempt to make someone believe that you will do something when you do not really intend to do it.
The letter was a bluff.
Bombast is trying to impress people by saying things that sound impressive but have little meaning.
There were men aboard who could not tolerate his bombast.
Thesaurus for bluster from the Collins English Thesaurus
If you say that someone is blustering , you mean that they are speaking aggressively but without authority, often because they are angry or offended .