last word       
noun [ S ] uk/ˌlɑːst ˈwɜːd/ us/ˌlæst ˈwɝːd/
 (辩论或讨论中的)最终的话,最后陈述
the final remark in an argument or discussion
  You're not going, Helena, and that's my last word on the matter. 你不能去,海伦娜,这事就这么定了。 
 She always has to have the last word (= win the argument). 她总是必须得赢。 
 Idiom   
be the last word in somethingidiom  最好的;最时尚(的事物)
to be the best or most modern example of something
  It's a nice enough restaurant and it's very reasonably priced but it's not exactly the last word in style. 这家餐厅很漂亮,价格也很合理,但是它的风格不怎么时尚。