I've heard "talking trash" as the common verb form, as well as "trash talking".I hadn't come across it before I came to this thread.
Does it work as a verb? Is it possible to say "Don't trash talk me"?
Another vote for "talk down"."Badmouth" might work, or "talking down (an opponent/rival)".
sourceOlympics: Australian official accuses British swimmers of bad hygiene
After Rebecca Adlington's 400m freestyle gold set the tone for Britain in the pool here, John Coates, the head of the Australian Olympic Committee and an International Olympic Committee member since 2001, was asked for his thoughts. "It's not bad for a country that has no swimming pools and very little soap," he said.
Just to explain: I understand this to be an example of 'trash talk', not an expression of englishjasmin's views. It contains two elements that characterize trash talk:You guys don't even know what is trash talk and you pretend to be able to advise others on English language and grammar? --- that's trash talk