From Longman Dictionary of Contemporary Englishblatherblath‧er /ˈblæðə $ -ər/ verb [intransitive] TALK TO somebodyto talk for a long time about unimportant things —blather noun [countable, uncountable]→ See Verb table
Examples from the Corpus
blather• He was thankful for the darkness of the cinema enveloping them so that he would no longer need to blather.• What are you blathering about, Doctor?• I seem to have been blathering on and on.Origin blather (1500-1600) Old Norse blathra 