sad是原型。

比较级sadder 最高级saddest

adj.悲哀的难过的让人无法接受的该受责备(或批评)的乏味的状况不佳的

It was sad that his international career should end in such anticlimax.

令人悲哀的是，他的国际职业生涯竟如此惨淡收场。