disastrous的基本意思是“灾难性的,坏的”,指人为的或自然的,具有很大的破坏性。

用作定语
▲～+n.
 Carelessness in driving often results in disastrous accidents.驾驶不慎常带来不幸的事故。
用作表语
▲S+be+～
 The road was disastrous.路面真糟糕。

［同义词］   fatal, unfortunate