Prattle
Definition 1 of 2
Pro Tip 1/3
Informality
Prattle, when used as a verb, is informal and implies trivial content of speech. He prattled on, unaware that nobody was interested.
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Conversational Context
Use 'prattle on' to describe someone speaking at length without substance, often annoyingly. My uncle always prattles on about the good old days.
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Subjectivity
Prattling can be a matter of opinion, what seems silly to one could be significant to another. She dismissed their concerns as prattling, though they felt quite serious about them.