To act like you’re better than everyone else, usually because you’ve got a bit of power, money, or a fancy title and you want the whole room to know it. Often paired with “over” someone, as in lording it over them. It’s not confidence, it’s pure smugness with a side of attitude.
"He got team lead on Monday and by Friday he’s lording it over everyone like he owns the gaff, wagging his lanyard and nicking the good biscuits"