disastrous

adjective

Causing great damage.

SYNONYMS

adverseappallingawfulbadblackcalamitouscataclysmiccatastrophicdarkdetrimentaldevastatingdiredreadfulgrievousharmfulhorribleill-fatedill-starredinauspiciousinjuriousravagingruinousshockingterribletragicunfavourableunfortunateunlucky