taunt
Z: So we've got two meaning for this word a remark made in order to anger, wound, or provoke someone.provoke or challenge (someone) with insulting remarks.
M: 有两种解释哈，第一种就是激怒，使某人生气。 第二种就是用一些带有侮辱性的话来挑战别人。

rant
M: Does the word has the same meaning with "complain"?
Z: Not exactly, the verb definition is speak or shout at length in a wild, impassioned way
you can complain while ranting.
wild 野蛮的，impassioned 激烈的


roast
M: Can we use that word to make fun of someone?
Z: Not so much to make fun of people, since it means to criticize or reprimand severely.
criticize 批评 reprimand 训斥

let off steam 宣泄
get something off one's chest 把...倾吐出来