Definition of smack talk in US English:

smack talk

noun

US
informal
  • Boastful or insulting speech, especially as intended to demoralize or humiliate an opponent.

    ‘a game like this promotes smack talk’
    • ‘Today, the pre-show hype, the smack-talking, and the arguments over the results are just as entertaining as bodybuilding shows themselves.’
    • ‘No doubt the crowd was piqued by the post-game smack-talking between Latrell Sprewell and Jon Barry, who woofed at each other jaw-to-jaw with a pitifully comic fervor reminiscent of weigh-ins at a heavyweight championship bout.’
    • ‘On a related note, I also play Fantasy Baseball, where you and your buddies draft twenty real-life layers and earn points based on their performances over a season - lots of good, old-fashioned smack-talk and wheelin' and dealin'.’
    • ‘The smack-talk between Kenyon and 'Toine is starting already.’
    • ‘What do you make of all the smack-talk between King Kamali and Craig Titus?’
    • ‘Another reason today's genteel banter is a far cry from the smack-talking of boxing's former glory days is that many fighters take their behavioral cues from the top dogs of the moment.’
    • ‘So look forward to more controversy, more smack-talking, and even more King, from both a physical and media standpoint, as he looks to come in bigger and better than ever.’

verb

[no object]US
informal
  • Make boastful or insulting remarks, especially in order to demoralize or humiliate an opponent.

    ‘I don't smack-talk — I'd rather just be playing hard and putting my focus on the game’
    • ‘Spiezio likes to have fun with players he knows, like Frank Menechino, Oakland's vertically challenged, smack-talking second baseman.’
    • ‘He knows that this role, that of the smack-talking kid you'd really like to smack, is one that will forever shape his image.’
    • ‘I’m not one to smack talk, but I did post a couple of mentions on Facebook about how cold Chicago was going to be, and said “Welcome to Chicago, Patriots” on my Twitter and Facebook.’
    • ‘The 21-year-old British sensation is neither flashy nor larger-than-life, forgoing glamour for a refreshingly unrefined persona as a smack-talking rabble-rouser.’
    • ‘Neal Henderson, my coach, and I were smack talking about the Iowa vs. Penn St game Sat night.’
    • ‘Nevertheless, in our regular Sunday class just prior to the race, the boys were smack-talking about how they were going to destroy their old man teacher on the coming Wednesday evening.’
    • ‘The ability to smack talk is a critical skill to being a successful fantasy sports coach.’
    • ‘Somebody has yet to convince me to see the new Steve Martin comedy, "Bringing Down the House" starring Martin in romantic lead with the smack-talking, but ever-loveable Queen Latifah.’