misfortune; calamity; disaster; opposite of 福 fú

Negative adverb used before verbs, adjectives, and other adverbs to indicate negation; also used as a bound-form prefix to form terms with opposite meanings

To occur individually or to travel alone; often used in the idiom 祸不单行 huò​bù​dān​xíng to describe misfortunes that do not come one at a time.