weighty  
adjective uk/ˈweɪ.ti/ us/ˈweɪ.t̬i/
  (HEAVY)      
  重的,沉重的
heavy
  I don't want to carry this bag around all afternoon - it's pretty weighty. 我不想整个下午到哪儿都带着这个包——它相当沉。 
   (SERIOUS)      
 重要的,重大的;严重的
A weighty subject, book, or piece of work is important or serious.
  weighty matters/issues 举足轻重的事件/问题