不測之事（名詞,，正式）

(noun, FORMAL) An unexpected and undesirable event; unfortunate accident; mishap.

EXAMPLE: A typhoon or other natural disaster can be a terrible contretemps for locals and tourists alike on tropical islands with economies that depend heavily on tourism.

在嚴重依賴旅游的熱帶島嶼，臺風或其它自然災害對當?shù)厝撕吐糜握邅碚f都是可怕的不測之事,。

side effect

副作用

Something unwanted that happens secondarily as the result of something else that is desired.

EXAMPLE: Unfortunately, a bad headache can be a side effect of the drug I must take for my illness.

真不幸,，嚴重的頭痛是我為治病不得不吃的藥物的副作用。