Trash talk is rude, boastful, insulting things you say to or about an opponent — usually to upset them or to show off. It comes from sport. A basketball player tells the other player he is slow and cannot shoot; that is trash talk. It works as a noun ('there was a lot of trash talk before the fight') and as a verb ('he trash-talked the other team all week'). Outside sport it has spread to video games, politics, and any competition where people insult each other in public. Two things make it different from ordinary insulting. First, it is expected — part of the game, almost a performance. Players and fans often enjoy it, and nobody is really supposed to be hurt. Second, it is loud and public, not quiet and cruel. Someone who says something nasty behind your back is not trash-talking; they are gossiping. You will see it written three ways: trash talk (two words), trash-talk (with a hyphen, usually as the verb), and trashtalk. Two words is the safest for the noun.

垃圾話（球場、電競上對對手的挑釁話）；嗆聲、嘴砲。台灣體育和電競圈直接說「垃圾話」或「嗆聲」，帶點玩笑性質，不完全是罵人