Means to trap someone in a long, one-way chat where they can’t get a word in. You can earbash a mate at the pub, or cop an earbash from that bloke who reckons he’s an expert on everything. Usually it’s boring, braggy, or unsolicited advice, and you’re just standing there praying your phone rings.
"Got cornered at the barbie and Barry earbashed me about his caravan upgrades. I nodded, necked two tinnies, and waited for someone to rescue me."