（空泛地）高谈阔论；夸夸其谈to talk or write in a way that shows that you think you know a lot and have sth important to say, when in fact you do not know much and have nothing important to say
v.
1.
tospeakatlengthinapompousself-aggrandizingway
1.
冗长演说
英语新词汇与常用词汇的翻译(B) ... blove 蓝色 bloviate冗长演说 blow a cloud 吞云吐雾 ...